ES2896765T3 - Process cartridge and electrophotographic imaging device - Google Patents

Abstract

Process cartridge removably mountable in a main assembly of an electrophotographic imaging apparatus, said process cartridge comprising: a photosensitive element; an engaging portion disposed at an end portion of said photosensitive member and including a driving force receiving portion for receiving a driving force for rotating said photosensitive member from outside said process cartridge; and a gear portion including gear teeth for receiving, independently of said coupling portion, a driving force from outside said process cartridge; wherein said gear teeth are helical gear teeth, and include an exposed portion exposed to the outside of said process cartridge, wherein at least a portion of said exposed portion is disposed outside of said force receiving portion drive, in an axial direction of said photosensitive element, and faces an axis of said photosensitive element, and wherein the shortest distance from the axis of said photosensitive element to a tooth tip of said gear portion, measured along along a direction perpendicular to the axis of said photosensitive element, is not less than 90%, and not more than 110% of a radius of said photosensitive element.

Description

DESCRIPTION

Process cartridge and electrophotographic imaging device

[TECHNICAL SECTOR]

The present invention relates to a process cartridge and an electrophotographic imaging apparatus using it.

In this case, the process cartridge is a cartridge that is integrally formed with a photosensitive element and a process medium that can act on the photosensitive element to be removably mounted to a main assembly of the electrophotographic imaging apparatus.

For example, a photosensitive member and at least one developing medium, charging medium and cleaning medium as processing means are integrally formed in one cartridge. Also, the electrophotographic imaging apparatus forms an image on a recording material using an electrophotographic imaging process.

Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, etc.), a facsimile, a word processor, and the like.

[PREVIOUS STATE OF THE ART]

In an electrophotographic imaging apparatus (hereinafter, also referred to simply as "imaging apparatus"), a drum-type electrophotographic photosensitive element as an image support element, that is, a photosensitive drum (electrophotographic photosensitive drum) is evenly loaded. Next, the charged photosensitive drum is selectively exposed to form an electrostatic latent image (electrostatic image) on the photosensitive drum. Next, the electrostatic latent image formed on the photosensitive drum is developed as a toner image, with toner as the developer. Next, the toner image formed on the photosensitive drum is transferred onto a recording material, such as a recording sheet, a plastic sheet, and the like, and heat and pressure are applied to the toner image transferred onto the material. to fix the toner image on the recording material, so that image recording is performed.

Such image forming apparatus generally requires replenishment of toner and maintenance of various processing means. In order to facilitate toner replenishment and maintenance, mountable process cartridges that can be removably mounted to the main assembly of the image forming apparatus have been put into cartridges by integrating photosensitive drums, charging media, developing media into the frame , cleaning media and the like.

With this process cartridge system, a part of the maintenance operation of the apparatus can be carried out by the user himself without depending on a maintenance person in charge of after-sales service. Therefore, it is possible to remarkably improve the ease of use of the apparatus, and it is possible to provide an image forming apparatus excellent in ease of use. For this reason, this process cartridge system is widely used with imaging apparatus.

As described in JP Patent H08-328449 (page 20, figure 16), a well-known imaging apparatus of the type described above includes a drive transmission element having a coupling at the free end thereof. for transmitting drive to the process cartridge from the main assembly of the imaging apparatus, which is spring biased towards the process cartridge. WO 2016/084986 A1 and US 2011/026971 A1 describe the state of the art with regard to drive transmission from the imaging apparatus to the process cartridge.

When an opening and closing door of the main assembly of the imaging apparatus is closed, the drive transmission member of this imaging apparatus is pressed by the spring and moves toward the process cartridge. Thereby, the drive transmission element engages (engages) with the process cartridge coupling, and drive transmission to the process cartridge is enabled. Also, when the opening/closing door of the main assembly of the imaging apparatus is opened, the drive transmission member moves in a direction away from the process cartridge against the spring by means of a cam. In this way, the drive transmission element disengages (engages) with the coupling of the process cartridge, so that the process cartridge can be removed from the main assembly of the imaging apparatus.

[CHARACTERISTICS OF THE INVENTION]

[PROBLEMS TO BE SOLVED BY THE INVENTION]

The object of the present invention is to further develop the aforementioned prior art.

[MEANS TO SOLVE THE PROBLEM]

A typical structure of the invention of this application will be described in claim 1. Further advantageous developments are set forth in the dependent claims.

[RESULT OF THE INVENTION]

It is possible to further develop the aforementioned prior art.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Fig. 1 is an illustration of a drive transmission part of a process cartridge according to embodiment 1.

Fig. 2 is a sectional view of the main assembly of the imaging apparatus and the process cartridge of the electrophotographic imaging apparatus according to Embodiment 1.

Figure 3 is a sectional view of the process cartridge according to embodiment 1.

Fig. 4 is a perspective view of the main assembly of the imaging apparatus in a state that the opening and closing door of the electrophotographic imaging apparatus according to Embodiment 1 is open.

Fig. 5 is a perspective view of the process cartridge and the driving side positioning part of the main assembly of the image forming apparatus, in a state that the process cartridge is mounted on the main assembly of the image forming apparatus; electrophotographic imaging apparatus, according to Embodiment 1.

Fig. 6 is an illustration of a connection part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 7 is an illustration of a connection part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 8 is a sectional view of a guide part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 9 is an illustration of a drive chain of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 10 is an illustration of a positioning part for positioning in a longitudinal direction in the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 11 is a positioning part of the electrophotographic imaging apparatus according to Embodiment 1.

Fig. 12 is a sectional view of a drive transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 13 is a perspective view of a driving transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 14 is a perspective view of a developing roller gear of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 15 is a perspective view of a driving transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 16 is a sectional view of a driving transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 17 is a sectional view around a drum of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 18 is a sectional view of a drive transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 19 is a perspective view of a drive transmission part of a process cartridge according to Embodiment 1.

Fig. 20 is a sectional view of the driving transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 21 is a perspective view of a development roller gear of the process cartridge according to Embodiment 1.

Fig. 22 is an illustration of a drive train of a process cartridge according to Embodiment 1. Fig. 23 is an illustration of the drive transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 24 is an illustration of the adjustment part of the electrophotographic image forming apparatus according to Embodiment 1.

Figure 25 is a cross-sectional view of the drive transmission part of the process cartridge according to Embodiment 1.

Fig. 26 is a perspective view of the adjusting part of the process cartridge according to Embodiment 1. Fig. 27 is an illustration of the adjusting part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 28 is an illustration of the driving transmission part of the electrophotographic image forming apparatus according to Embodiment 1.

Fig. 29 is a perspective view of the regulation part of the electrophotographic image forming apparatus according to Embodiment 2.

Fig. 30 is an illustration of the adjustment part of the electrophotographic image forming apparatus according to Embodiment 2.

Fig. 31 is an illustration of the adjustment part of the electrophotographic image forming apparatus according to Embodiment 2.

Fig. 32 is an illustration of the adjustment part of the electrophotographic image forming apparatus according to Embodiment 2.

Fig. 33 is an illustration of the process cartridge according to Embodiment 1.

Fig. 34 is an illustration of the process cartridge according to Embodiment 1.

Fig. 35 is an illustration of a modified example of Embodiment 1.

Fig. 36 is an illustration of a modified example of Embodiment 1.

Fig. 37 is a perspective view showing a gear part and a coupling part in Embodiment 1.

Fig. 38 is a perspective view showing a modification of Embodiment 1.

Figure 39 is an illustration of the device, according to embodiment 2.

[DETAILED DESCRIPTION OF THE INVENTION]

<Embodiment 1>

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The direction of the axis of rotation of an electrophotographic photosensitive drum is defined as the longitudinal direction. In the longitudinal direction, the side where the electrophotographic photosensitive drum receives the driving force from the main assembly of the image forming apparatus is a driving side, and the side opposite thereto is a non-driving side.

Referring to Fig. 2 and Fig. 3, the overall structure and imaging process will be described.

Fig. 2 is a cross-sectional view of the electrophotographic imaging apparatus main assembly (the electrophotographic imaging apparatus main assembly, the imaging apparatus main assembly A) and the process cartridge ( hereinafter referred to as cartridge B) of the electrophotographic imaging apparatus, according to an embodiment of the present invention.

Figure 3 is a cross-sectional view of cartridge B.

In this case, the main assembly of the apparatus A is a part of the electrophotographic imaging apparatus, excluding the cartridge B.

<Comprehensive configuration of electrophotographic imaging apparatus>

An electrophotographic imaging apparatus (imaging apparatus) shown in Fig. 2 is a laser beam printer using an electrophotographic process in which the cartridge B is removably mounted in the main assembly of the apparatus A. An exposure device 3 (laser scanner unit) is arranged to form a latent image on the electrophotographic photosensitive drum 62, as the image supporting member of the cartridge B, at the time the cartridge B is mounted on the main assembly. of the apparatus A. Also, under the cartridge B, a sheet tray 4 containing recording materials (hereinafter referred to as sheet material PA) to be imaged is provided. The electrophotographic photosensitive drum 62 is a photosensitive element (electrophotographic photosensitive element) used to form an electrophotographic image.

Furthermore, in the main assembly of the apparatus A, a pick-up roller 5a, a feed roller pair 5b, a feed roller pair 5c, a transfer guide 6, a transfer roller 7, a feed guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, and the like are arranged sequentially. Furthermore, the fixing device 9 comprises a heating roller 9a and a pressure roller 9b.

<Imaging process>

Next, the imaging process will be briefly explained. Based on the print start signal, the electrophotographic photosensitive drum (hereinafter referred to as photosensitive drum 62 or simply drum 62) is rotatably driven in the direction of an arrow R at a predetermined circumferential speed (speed of rotation). process).

The charging roller 66 (charging element), to which the bias voltage is applied, contacts the outer peripheral surface of the drum 62 to uniformly charge the outer peripheral surface of the drum 62. The exposure device 3 emits a beam of laser L according to the information in the image. The laser beam L passes through the laser opening 71h provided in the cleaning frame 71 of the cartridge B, and scans the outer peripheral surface of the drum 62 incident thereon. Thereby, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum 62.

On the other hand, as shown in Fig. 3, in the developing unit 20 as a developing device, the toner T in the toner chamber 29 is stirred and fed by rotating the feed member 43 (shaker member) at a toner supply chamber 28.

The toner T is carried on the surface of the developing roller 32 by the magnetic force of the magnet roller 34 (stationary magnet). The developing roller 32 is a developer transport member which transports a developer (toner T) on the surface thereof, to develop a latent image formed on the drum 62. While the toner T is triboelectrically charged by the developing roller 42, the thickness of the layer on the peripheral surface of the developing roller 32, as a developer conveying member, is regulated.

The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, to develop the latent image. In this way, the latent image is displayed in a toner image. The drum 62 is an image supporting member for transporting the latent image and the image (toner image, developer image) formed with toner on the surface thereof. Also, as shown in Fig. 2, the sheet material PA stored in the lower part of the main apparatus assembly A is dispensed from the sheet tray 4 in synchronous relation to the output of the laser beam L, by the roller pick-up roller 5a, the pair of feed rollers 5b and the pair of feed rollers 5c. Next, the PA sheet material is fed to the transfer position between the drum 62 and the transfer roller 7 along the transfer guide 6. In this transfer position, the toner image is sequentially transferred from the drum 62 to PA sheet material.

The PA sheet material to which the toner image is transferred is separated from the drum 62 and fed to the fixing device 9 along a transport guide 8. And the PA sheet material passes through the nip portion between a heating roller 9a and a pressure roller 9b constituting the fixing device 9. In this clamping part, pressure and heat fixing processes are carried out, so that the toner image is fixed on the PA material of leaves. The PA sheet material subjected to the toner image fixing process is fed to the pair of discharge rollers 10 and discharged to the discharge tray 11.

On the other hand, as shown in Fig. 3, after image transfer, residual toner remaining on the outer circumferential surface of drum 62 after transfer is removed by cleaning blade 77 and used again. for the imaging process. The toner removed from the drum 62 is stored in a waste toner chamber 71b of the cleaning unit 60. The cleaning unit 60 is a unit including the photosensitive drum 62.

In the above description, the charge roller 66, the development roller 32, the transfer roller 7 and the cleaning blade 77 act as a process medium acting on the drum 62.

<Integer cartridge structure>

The overall structure of cartridge B will now be described with reference to Figures 3, 4 and 5. Figure 3 is a sectional view of cartridge B, and Figure 4 and Figure 5 are perspective views showing show the structure of the cartridge B. In the description of this embodiment, the screws for joining the parts are omitted.

Cartridge B includes a cleaning unit 60 (photosensitive element holding unit, drum holding unit, image supporting element holding unit, first unit) and a developing unit 20 (carrier holding unit). developer, second unit).

Generally, the process cartridge is a cartridge in which at least one of the electrophotographic photosensitive element and the process medium acting thereon are integrally formed in one cartridge, and the process cartridge can be mounted in, and remove from the main assembly (main assembly of the apparatus) of the electrophotographic imaging apparatus. Examples of the process media include charging media, developing media, and cleaning media.

As shown in Fig. 3, the cleaning unit 60 includes a drum 62, a charge roller 66, a cleaning member 77, and a cleaning frame 71 for supporting them. On the drive side of the drum 62, the drive side drum flange 63 provided on the drive side is rotatably supported by the hole 73a of the drum support 73. In a broad sense, the drum support 73 plus the cleaning frame 71 can be called a cleaning frame.

As shown in Fig. 5, on the non-drive side, the bore portion (not shown) of the non-drive side drum flange is rotatably supported by the drum shaft 78, press fitted into the hole portion 71c is arranged in the cleaning frame 71, and is formed to be supported.

Each flange of the drum is a supported part, rotatably supported by the support part.

In the cleaning unit 60, the charge roller 66 and the cleaning member 77 are disposed in contact with the outer peripheral surface of the drum 62.

The cleaning member 77 includes a rubber blade 77a which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 77b supporting the rubber blade. The rubber blade 77a is in reverse contact with the drum 62, relative to the direction of rotation of the drum 62. In other words, the rubber blade 77a is in contact with the drum 62, so that the part of the tip thereof is facing the upstream side in the direction of rotation of the drum 62.

As shown in Fig. 3, the waste toner removed from the surface of the drum 62 by the cleaning member 77 is stored in the waste toner chamber 71 b formed by the cleaning frame 71 and the cleaning member 77.

Also, as shown in Fig. 3, a collecting plate 65 for preventing residual toner from leaking from the cleaning frame 71 is provided on the edge of the cleaning frame 71 to contact the drum 62.

The charge roller 66 is rotatably mounted to the cleaning unit 60 by means of charge roller holders (not shown) at opposite end portions in the longitudinal direction of the cleaning frame 71. In addition, the longitudinal direction of the cleaning frame 71 (the longitudinal direction of the cartridge B) is substantially parallel to the direction (the axial direction) in which the axis of rotation of the drum 62 extends. Therefore, in the case of simply referring to the longitudinal direction , or simply the axial direction, without further specification, means the axial direction of the drum 62.

Charge roller 66 is pressed against drum 62 as charge roller support 67 is pressed toward drum 62 by biasing member 68. Charge roller 66 is rotatably driven by drum 62. As shown As shown in Fig. 3, the developing unit 20 includes a developing roller 32, a developing container 23 supporting the developing roller 32, a developing blade 42, and the like. The developing roller 23 is rotatably mounted to the developing container 23 by support members 27 (FIG. 5) and 37 (FIG. 4) provided at opposite ends.

Also, a magnet roller 34 is provided inside the developing roller 32. In the developing unit 20, a developing blade 42 is provided for regulating the layer of toner on the developing roller 32. As shown in 4 and Fig. 5, the gap keeping member 38 is mounted on the developing roller 32 at the opposite end portions of the developing roller 32, and the gap keeping member 38 and the drum 62 are in contact with each other, so that the development roller 32 is kept with a small gap from the drum 62. Also, as shown in Fig. 3, a leak prevention plate 33 to prevent toner from leaking from the developing unit 20 is arranged on the edge of the lower member 22 to be in contact with the developing roller 32. In addition, in the toner chamber 29 formed by the developer container 23 and the lower member 22, a toner chamber 29 is provided. feed member 43. The feed member 43 stirs the toner in the toner chamber 29 and transports the toner to the toner supply chamber 28.

As shown in Figs. 4 and 5, cartridge B is formed by combining the cleaning unit 60 and developing unit 20.

In the first step for attaching the developing unit and the cleaning unit to each other, the center of the first developing support protrusion 26a of the developing container 23 is aligned with each other with respect to the first suspension hole 71 i on the side. cleaning frame drive 71, and the center of the second protrusion of revealed 23b with respect to the second suspension hole 71j on the non-drive side. More particularly, by moving the developing unit 20 in the direction of the arrow G, the first developing support protrusion 26a and the second developing support protrusion 23b fit into the first suspension hole 71i and the second suspension hole 71j. Thereby, the developing unit 20 is movably connected with the cleaning unit 60. More specifically, the developing unit 20 is rotatably (rotatably) connected to the cleaning unit 60. After this, the cartridge B It is constructed by mounting the drum support 73 on the cleaning unit 60.

Also, the first end part 46La of the drive side deflection member 46L is fixed to the surface 23c of the developing container 23, and the second end part 46Lb abuts against the surface 71k which is a part of the developing unit. cleaning.

Also, the first end 46Ra of the non-drive side deflection member 46R is fixed to the surface 23k of the developing container 23, and the second end 46Rb is in contact with the surface 711 which is a part of the cleaning unit.

In this embodiment, the drive side biasing member 46L (FIG. 5) and non-drive side biasing member 46R (FIG. 4) comprise compression springs, respectively. The urging force of these springs urges the developing unit 20 against the cleaning unit 60 to reliably push the developing roller 32 toward the drum 62 by the driving side urging member 46L and the driving side urging member 46L. not drive 46R. Next, the developing roller 32 is kept at a predetermined distance from the drum 62 by the gap keeping members 38 mounted on opposite end portions of the developing roller 32.

<Cartridge mounting>

Next, the assembly of the cartridge will be explained in detail with reference to parts (a) and (b) of Fig. 1, part (a) of Fig. 6, part (b) of Fig. 6, part (c) of Figure 6, part (a) and part (b) of Figure 8, part (b) of Figure 8, part (a) of Figure 9, part (a) of Figure 10 and part (b) of Figure 10, part (a) of Figure 11, part (a) and part (b) of Figure 12, part (a) of Figure 13, part (b) of figure 13, figure 14, figure 15, figure 16 and figure 17. Part (a) and part (b) of figure 1 are perspective views of cartridges for explain the way around the drive transmission part. Part (a) of figure 6 is a perspective view of a cylindrical cam, part (b) of figure 6 is a perspective view of the drive side plate seen from the outside of the assembly apparatus A, and part (c) of Fig. 6 is a sectional view in which a cylindrical cam is mounted on the drive side plate (the direction indicated by the arrow in part (b) of figure 6). Part (a) of Fig. 7 is a cross-sectional view of the connection part of the image forming apparatus for explaining the connection structure, and part (b) of Fig. 7 is a view, in cross section, of the drive unit of the imaging apparatus, to explain the movement of the drive transmission member. Part (a) of Fig. 8 is a cross-sectional view of the driving side guide part of the imaging apparatus for explaining the mounting of the cartridge, and part (b) of Fig. 8 is a cross-sectional view of the non-drive side guide portion of the imaging apparatus for explaining the mounting of the cartridge. Fig. 9 is an illustration of the drive train part of the imaging apparatus, for explaining the positional relationship of the drive train before the closing of the open/close door. Part (a) of Fig. 10 is an illustration immediately before the engagement of the positioning part of the image forming apparatus, to explain the positioning of the process cartridge B in the longitudinal direction. Part (b) of Fig. 10 is an illustration after engagement of the positioning part of the image forming apparatus, to explain the positioning of the process cartridge B in the longitudinal direction. Part (a) of Fig. 11 is a cross-sectional view of the drive side of the image forming apparatus to explain the positioning of the cartridge. Part (b) of Fig. 11 is a sectional view of the non-drive side of the image forming apparatus for explaining the positioning of the cartridge. Part (a) of Fig. 12 is a cross-sectional view of the connection part of the image forming apparatus for explaining the connection structure, and part (b) of Fig. 12 is a view, in cross section, of the driving part of the image forming apparatus, to explain the movement of the driving transmission member. Part (a) of Fig. 13 is a perspective view of the drive transmission member to explain the shape of the drive transmission member. Part (b) of Fig. 13 is an illustration of the drive transmission part of the main assembly A, to explain the drive transmission part. Fig. 15 is a perspective view of a drive unit of the image forming apparatus for explaining the engagement space of the drive transmission part. Fig. 16 is a cross-sectional view of the drive transmission member to explain the engagement space of the drive transmission member. Fig. 17 is a sectional view around the drum 62 of the main assembly of the apparatus A, for explaining the gear arrangement of the developing roller. Fig. 18 is a cross-sectional view of the drive transmission member for explaining the engagement of the drive transmission member.

First, a state in which the opening/closing door of the main assembly of the apparatus A will be described. it's open. As shown in part (a) of Fig. 7, an opening/closing door 13, a cylindrical cam connection 85, a cylindrical cam 86, pressure members 1, 2 of the cartridge, pressure springs 19, 21 of the cartridge and a front plate 18. Also, as shown in part (b) of Fig. 7, a support 83 of the transmission element is arranged in the main assembly A of the device. drive transmission member 81, a drive transmission member bias spring 84, a drive side plate 15 and a non-drive side plate 16 (part (a) of Fig. 10).

The opening/closing door 13 is rotatably mounted on the drive side plate 15 and the non-drive side plate 16. As shown in part (a) of Fig. 6, part (b) of Fig. 6 and part (c) of Fig. 6, the cylindrical cam 86 is rotatable on the drive side plate 15 and is movable in the longitudinal direction AM, and has two inclined surface portions 86a, 86b and, furthermore, it has an end portion 86c continuous with the slope on the non-drive side in the longitudinal direction. The drive side plate 15 has two inclined surface portions 15d and 15e opposite the two inclined surface portions 86a and 86b, and an end surface 15f opposite the end portion 86c of the cylindrical cam 86. As shown in part (a) of Fig. 7, the cylindrical cam connection 85 is provided with protrusions 85a, 85b at opposite ends. The protrusions 85a, 85b are rotatably mounted on the mounting hole 13a provided on the opening/closing door 13 and the mounting hole 86e provided on the cylindrical cam 86, respectively. When the opening and closing door 13 is rotated and opened, the rotary cam link 85 moves in interrelation with the open/close door 13. The cylindrical cam 86 is rotated by movement of the link 85 of the rotating cam, and the inclined surfaces 86a, 86b first come into contact with the inclined surface portions 15d, 15e provided on the drive side plate 15. When the cylindrical cam 86 rotates further, the inclined surface portions 86a, 86b slide along the inclined surface portions 15d, 15e, so that the cylindrical cam 86 moves to the driving side in the longitudinal direction. Finally, the cylindrical cam 86 moves until an end portion 86c of the cylindrical cam 86 abuts against the end surface 15f of the drive side plate 15.

In this case, as shown in part (b) of Fig. 7, the drive transmission member 81 is mounted on the drive transmission member support 83 at one end (fixed end 81c) on the drive side. drive in the axial direction, and is supported to be rotatable and movable in the axial direction. Also, in the drive transmission member 81, the center portion 81d in the longitudinal direction has a clearance M relative to the drive side plate 15. Also, the drive transmission member 81 has a bearing surface 81e, and the cylindrical cam 86 has the other end portion 86d opposite the bearing surface 81e. The drive transmission element spring 84 is a compression spring, in which one end portion 84a is in contact with a spring seat 83a, arranged in the drive transmission element support 83, and the other end portion 84b The end contact is in contact with a spring seat 81f arranged in the drive transmission member 81. Thereby, the drive transmission member 81 is pushed toward the non-drive side in the axial direction (left side in the upper part). (b) of Figure 7). By this thrust, the bearing surface 81e of the drive transmission member 81 and the other end portion 86d of the cylindrical cam 86 are in contact with each other.

When the cylindrical cam 86 moves in the longitudinal direction towards the drive side (the right side in part (b) of Fig. 7), the drive transmission member 81 is pushed by the cylindrical cam 86 and moves towards the drive side, as described above. This causes the drive transmission element 81 to be in the retracted position. In other words, the drive transmission member 81 is removed from the movement path of the cartridge B, thereby ensuring the space for mounting the cartridge B on the main assembly A of the imaging apparatus.

Next, the assembly of the cartridge B will be described. As shown in part (a) of Fig. 8 and part (b) of Fig. 8, the driving side plate 15 has an upper guide rail 15g and a guide rail 15h as guide means, and the non-drive side plate 16 has a guide rail 16d and a guide rail 16e. Also, the drum holder 73 provided on the drive side of the cartridge B has a guided portion 73g and a rotation-stop portion 73c. In the mounting direction of the cartridge B (arrow C), the guided part 73g and the rotation stopping part 73c are arranged on the upstream side of the axis of the coupling boss 63b (see part (a) of the figure). 1, details will be described below) (side of arrow AO in Fig. 16).

The direction in which the cartridge B is mounted is substantially perpendicular to the axis of the drum 62. In a case where reference is made to upstream or downstream in the mounting direction, upstream and downstream are defined in the direction of the movement of cartridge B immediately before assembly into the main assembly of apparatus A is completed.

Further, the cleaning frame 71 is provided with a positioned part 71d (a part to be positioned) and a stopped rotation part 71g on the non-drive side in the longitudinal direction. When the cartridge B is mounted through the cartridge inserting hole 17 of the main assembly of the apparatus A, the guided part 73g and the rotation stopper portion 73c on the driving side of the cartridge B are guided by the guide rail 15g and the lane of guide 15h of the main assembly A. On the non-driving side of the cartridge B, the positioned part 71d and the stopped rotation part 71g are guided by the guide rail 16d and the guide rail 16e of the main assembly of the apparatus A. In this way, the cartridge B is mounted in the main assembly of the apparatus A.

In this case, a developing roller gear 30 (developing gear) is provided at the end part of the developing roller 32 (FIG. 9 and part (b) of FIG. 13). That is, the development roller gear 30 is mounted on the shaft portion (shaft) of the development roller 32.

The development roller 32 and the development roller gear 30 are coaxial with each other and rotate about the axis Ax2 shown in Fig. 9. The development roller 32 is arranged such that the axis Ax2 thereof is substantially parallel to the development roller 32. axis Ax1 of the drum 62. Therefore, the axial direction of the developing roller 32 (developing roller gear 30) is substantially the same as the axial direction of the drum 62.

The developing roller gear 30 is a drive input gear (a cartridge-side gear, a drive input member) to which a driving force is delivered from outside the cartridge B (that is, the main assembly of device A). The development roller 32 is rotated by the driving force received by the development roller gear 30.

As shown in part (a) and part (b) of Fig. 1, an open space 87 is provided on the drive side side of the cartridge B on the drum 62 side of the developing roller gear 30 , so that the developing roller gear 30 and the engaging projection 63b are exposed to the outside.

The coupling projection 63b is formed on the drive side drum flange 63 mounted on the end of the drum (FIG. 9). The coupling protrusion 63b is a coupling part (drum side coupling part, cartridge side coupling part, photosensitive element side coupling part, input coupling part, drive input part) (Fig. 9), to which a driving force is introduced from outside the cartridge B (ie, the main assembly of the apparatus A). The coupling projection 63b is disposed coaxially with the drum 62. In other words, the coupling projection 63b rotates about the axis Ax1.

The drive-side drum flange 63 including the coupling protrusion 63b may be called a coupling element (a drum-side coupling element, a cartridge-side coupling element, a cartridge-side coupling element). photosensitive, a drive input coupling element, an input coupling element).

Also, in the longitudinal direction of the cartridge B, the side on which the engaging projection 63b is provided is the drive side, and the opposite side corresponds to the non-drive side.

Also, as shown in Fig. 9, the developing roller gear 30 has a gear part 30a (input gear part, cartridge side gear part, development side gear part) and a surface drive side end 30a1 of the gear part (part (a), part (b) of Fig. 9 and Fig. 1). The teeth (gear teeth) formed on the outer periphery of the gear portion 30a are helical teeth inclined with respect to the axis of the developing roller gear 30. In other words, the developing roller gear 30 is a helical-toothed gear (part (a) in Fig. 1). In this case, the helical tooth also includes a shape in which a plurality of projections 232a are arranged along a line inclined to the gear axis, to substantially form the helical tooth portion 232b (FIG. 14). In the structure shown in Fig. 14, the gear 232 has a large number of projections 232b on its circumferential surface. And the set of five projections 232b can be considered to form an inclined row with respect to the gear axis. Each of the rows of these five projections 232b corresponds to the tooth of the aforementioned gear part 30a.

The drive transmission member 81 (drive output member, main assembly side drive member) has a gear part 81a (main assembly side gear part, output gear part) for driving the gear 30 of the development roller. The gear part 81a has an end surface 81a1 at the non-drive side end (part (a), part (b) of Fig. 13).

The teeth (gear teeth) formed on the gear part 81a are also helical teeth inclined with respect to the axis of the drive transmission member 81. In other words, the worm gear part is also arranged on the drive transmission member 81.

Also, the drive transmission member 81 is provided with a coupling recess 81b. The coupling recess 81b is a coupling part (main assembly side coupling part, outlet coupling part) provided on the main assembly side of the device. The engaging recess 81b is made by forming a recess that can be engaged with an engaging projection 63b provided on the drum side, on a projection (cylindrical portion) provided on the free end portion of the member. drive transmission 81.

The space (gap) 87 (FIG. 1), formed so that the gear portion 30a and the engagement projection 63b are exposed, allows the gear portion 81a of the drive transmission member 81 to be positioned when the cartridge is mounted. B in the main assembly of the apparatus A. Therefore, the gap 87 is larger than the gear portion 81a of the drive transmission member 81 (FIG. 15).

More specifically, in the cross section of the cartridge B passing through the gear portion 30a and being perpendicular to the axis of the drum 62 (the axis of the coupling boss 63b), an imaginary circle having the same radius as that of the gear part 81a is drawn around the axis of the drum 62 (the axis of the coupling projection 63b). Then, the interior of the imaginary circle is a space in which there is no constituent element of the cartridge B. The space defined by this imaginary circle is included in the space 87 mentioned above. That is, the space 87 is larger than the space defined by the imaginary circle.

What follows is the explanation of this, in another way. In the above cross section, an imaginary circle concentric with the drum 62 (coaxially) is drawn, having a radius of the distance from the axis of the drum 62 to the tooth tip of the gear portion 30a of the developing roller 30. Then, the interior of this imaginary circle is a space (space) in which there are no constituent elements of cartridge B.

Since the space 87 exists, the drive transmission member 81 does not interfere with the cartridge B when the cartridge B is mounted on the main assembly of the apparatus A. As shown in Fig. 15, the space 87 allows the mounting of the cartridge B. cartridge B into the main apparatus assembly A by placing the drive transmission member 81 therein.

Also, as the cartridge B is viewed along the axis line of the drum 62 (the axis of the engaging projection 63b), the gear teeth formed on the gear portion 30a are arranged at a position close to the peripheral surface of drum 62.

As shown in Fig. 16, a distance AV (the distance along the direction perpendicular to the axis) from the axis of the drum 62 to the free end portion of the gear tooth of the gear portion 30a (toe of the gear). tooth) is 90% or more and 110% or less than the drum radius 62.

In particular, in this embodiment, the radius of the drum 62 is 12 mm, and the distance from the axis of the drum 62 to the gear tooth free end portion of the gear portion 30a (tooth tip) is 11.165 mm or more, and 12.74 or less. In other words, the distance from the axis of the drum 62 to the gear tooth free end portion of the gear portion 30a (tooth tip) is within the range of 93% to 107% of the radius of the drum.

In the longitudinal direction, the end surface 30a1 of the gear portion 30a of the developing roller gear 30 is arranged to be positioned at a position closer to the drive side (outside the cartridge B) than the front end portion 63b1 of the cartridge B. drive side drum flange 63 engagement boss 63b (FIG. 9, FIG. 33).

Hereby, in the axial direction of the developing roller gear 30, the gear teeth of the gear part 30a have exposed portions, exposed from the cartridge B (FIG. 1). Especially in this embodiment, as shown in Fig. 16, an interval of 64° or more of the gear portion 30a is exposed. In other words, when a line connecting the center of the drum 62 and the center of the developing roller gear 30 is taken as the reference line, as the cartridge B is viewed from the drive side, both sides of the roller gear 30 of development with respect to this reference line are exposed, at least in a range of 32 degrees or more. In Fig. 16, the angle AW indicates the angle from the reference line to the position where the gear portion 30a begins to be covered by the drive side developing side member 26 with the center (axis) of the gear 30 development roller as the origin, and AW > 32° is satisfied. The total exposure angle of the gear portion 30a can be expressed as 2AW, and as described above, the relationship 2AW > 64° is satisfied.

If the gear portion 30a of the developing roller gear 30 is exposed from the drive side developing side member 26 to meet the above relationship, the gear portion 81a engages with the gear portion 30a without interfering with the development side element of drive side 26. And therefore drive transmission is possible.

And at least a part of the exposed part of this gear part 30a is disposed further to the outside (drive side) of the cartridge B than the front end 63b1 of the coupling projection 63b, and faces the axis of the drum (FIG. 1 , figure 9, figure 33). In Figs. 9 and 33, the gear teeth arranged on the exposed portion 30a3 of the gear portion 30a face the axis of rotation Ax1 of the drum 62 (axis of rotation of the coupling portion 63b) Ax1. In Fig. 33, the axis Ax1 of the drum 62 is above the exposed part 30a3 of the gear part 30a.

In Fig. 9, at least a part of the gear part 30a protrudes toward the driving side beyond the coupling projection 63b in the axial direction, so that the gear part 30a overlaps the gear part 81a of the engine. drive transmission element 81 in the axial direction. And a part of the gear part 30a is exposed to face the axis Ax1 of the drum 62, and therefore the gear part 30a and the gear part 81a of the drive transmission member 81 can come into contact with each other at the course of introducing the cartridge B into the main assembly of the apparatus A.

Fig. 33 shows a state in which the outer end portion 30a1 of the gear portion 30a is disposed on the arrow D1 side of the free end portion 63b1 of the coupling projection 63b. Arrow D1 extends outward in the axial direction.

Due to the arrangement relationship described above, the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the drive transmission member 81 can be put into interlocking mesh with each other in the process of mounting the cartridge B described above in the main assembly of the apparatus A. In addition, in the mounting direction C of the cartridge B, the center (axis) of the gear portion 30a is disposed on the upstream side (the side of the arrow AO in figure 16) from the center (axis) of the drum 62.

The arrangement of the development roller gear 30 will be described in greater detail. As shown in Fig. 17, which is a sectional view seen from the non-drive side, the line connecting the center of the drum 62 and the center of the charge roller 66 is defined as a reference line ( initial line) that provides the angular reference (0°). At this time, the center (axis) of the developing roller gear 30 is in the angular range of 64° to 190° from the reference line to the downstream side of the direction of rotation of the drum 62 (clockwise in Fig. 17).

Strictly speaking, the half line extending from the center of the drum 62 to the center of the charge roller 66 relative to the center of the drum 62 is taken as the starting line, and the direction of rotation of the drum is taken as a positive direction. of the angle. Then, the angle on the polar coordinate formed around the center of the developing roller satisfies the following relationship.

64° < angle about polar coordinates having development roller center < 190°.

There is a certain degree of latitude in the charge roller 66 arrangement and the development roller gear 30 arrangement. The angle when the charge roller 66 and the development roller gear 30 are closest to each other is indicated by an arrow BM and, as described above, is 64° in this embodiment. On the other hand, the angle when the two are furthest from each other is indicated by an arrow BN, which is 190° in this embodiment.

Further, as described above, the unit (developing unit 20) provided with the developing roller gear 30 can be moved with respect to the unit (cleaning unit 60) provided with the drum 62 and the engaging projection 63b. That is, the developing unit 20 is rotatable with respect to the cleaning unit 60 about the first developing support protrusion 26a and the second developing support protrusion 23b (Figs. 4, 5) as the center of rotation (axis of rotation). Therefore, the distance between the centers of the developing roller gear 30 and the drum 62 (the distance between the axes) is variable, and the developing roller gear 30 can move within a certain range with respect to the drum axis. drum 62 (the axis of the coupling projection 63b).

As shown in Fig. 9, when the gear part 30a and the gear part 81a come into contact with each other during the process of inserting the cartridge B, the gear part 30a is pushed by the gear part 81a to be away from the axis of the drum 62 (the axis of the coupling projection 63b). This weakens the impact of the contact between the gear part 30a and the gear part 81a.

As shown in part (a) of Fig. 10 and part (b) of Fig. 10, the drum support 73 is provided with an engaging part 73h (engaging part) as well as a positioning part (aligned part). axial) in the longitudinal direction (axial direction).

The drive side plate 15 of the apparatus main assembly A has an engaging part 15j which can engage with the engaging part 73h. The geared part 73h of the cartridge B meshes with the gearing part 15j of the main assembly of the apparatus A in the assembly process described above, so that the position, in the longitudinal direction (axial direction), of the cartridge B is determined ( part (b) of figure 10). Also, in this embodiment, the engaged portion 73h is in the form of a slit (groove) (part (b) of Fig. 1). This slit communicates with the space 87. That is, the slit (the embedded part 73h) forms an open space (open) to the space 87.

Referring to Fig. 33, the position of the engaged portion 73h will be described in detail. Figure 33 is an illustration (schematic diagram) showing the arrangement of the gear portion 73h with respect to the gear portion 30a or the engagement boss 63b. As shown in Fig. 33, the slit (engaged portion 73h) is a space formed between two portions (the outer portion 73h1 and the inner portion 73h2 of the engaged portion 73h) arranged along the axial direction. In the axial direction, the inner end part (the inner part 73h2) of the gear part 73h is disposed inside (on the arrow D2 side) of the outer end part 30a1 of the gear part 30a. In the axial direction, the outer end part (outer part 73h1) of the embedded part 73h is disposed on the outermost side (arrow D1 side) than the free end part 63b of the coupling projection 63b.

Next, the closing state of the door 13 will be described. As shown in part (a) of Fig. 8, part (b) of Fig. 8, part (a) of Fig. 11, and part (a) of Fig. part (b) of Fig. 11, the drive side plate 15 has an upper locating part 15a, a lower locating part 15b, and a rotation stopper part 15c. As the positioning part, the non-drive side plate 16 has a positioning part 16a and a rotation stop part 16c. The drum support 73 includes an upper positioning part 73d (positioning part) (a first positioning part (positioning part), a first protrusion, a first projecting part), a lower positioning part 73f (positioning part) (a second part to be positioned (positioned part), a second protrusion, a second cantilevered part).

Also, the cartridge pressure members 1 and 2 are rotatably mounted on the opposite axial ends of the opening/closing door 13. The cartridge pressure springs 19, 21 are mounted on the opposite ends in the longitudinal direction of the front plate disposed in the imaging apparatus A, respectively. The drum support 73 is provided with a pressing part 73e (pressed part) as the pushing force receiving part, and the cleaning frame 71 has a pressing part 71o (pressed part) on the non-drive side. (figure 3). When closing the door 13, the pressed parts 73e, 71o of the cartridge B are pressed by the pressing elements 1, 2 of the cartridge pushed by the pressing springs 19, 21 of the cartridge of the main assembly of the apparatus A.

Thus, on the drive side, the upper positioned member 73d, the lower positioned member 73f, and the rotation stop member 73c of cartridge B come into contact with the upper locating part 15a, the lower locating part 15b, the rotation stop part 15c, respectively. With this, the cartridge B and the drum 62 are mutually positioned on the drive side. Also, on the non-drive side, the positioning part 71d of the cartridge B and the rotation stop part 71g come into contact with the positioning part 16a and the rotation stop part 16c of the main assembly of the apparatus A, respectively. . In this way, cartridge B and drum 62 are positioned relative to each other on the non-drive side. As shown in part (a) and part (b) of Fig. 1, the upper positioned member 73d and the lower positioned member 73f are located in proximity to the drum. Also, the upper positioned member 73d and the lower positioned member 73f are aligned along the direction of rotation of the drum 62.

Also, in the drum support 73, it is necessary to ensure a space (arcuate recess) 73l for arranging the transfer roller 7 (FIG. 11) between the upper positioned part 73d and the lower positioned part 73f. Therefore, the upper positioned part 73d and the lower positioned part 73f are disposed apart from each other. Also, the upper positioned part 73d and the lower positioned part 73f are protrusions protruding inwardly in the axial direction from the drum support 73. As described above, it is necessary to ensure a space 87 around the coupling projection 63b. Therefore, the upper positioned part 73d and the lower positioned part 73f do not protrude outward in the axial direction, but instead protrude inward to ensure the space 87.

The upper positioned part 73d and the lower positioned part 73f are protrusions arranged to partially cover the photosensitive drum 62. In other words, the positioned parts 73d, 73f are cantilevered parts protruding inward in the axial direction of the photosensitive drum 62. When the upper positioned part 73d and the photosensitive drum 62 project on the axis of the drum 62, at least part of the projected areas of the upper positioned part 73d and the photosensitive drum 62 overlap each other. In this respect, the lower positioned part 73f is the same as the upper positioned part 73d.

Also, the upper positioned part 73d and the lower positioned part 73f are arranged to partially cover the drive side drum flange 63 provided at the end of the photosensitive drum 62. When the upper positioned part 73d and the drive side drum flange 63 The drive sides project onto the drum axis 62, at least part of the projected areas of the upper positioned portion 73d and the drive side drum flange 63 overlap each other. In this respect, the lower positioned part 73f is the same as the upper positioned part 73d.

The pressed parts 73e and 71o are protruding parts of the cleaning unit frame provided at one end side (drive side) and the other end side (non-drive side) of the cartridge B with respect to the longitudinal direction, respectively. Especially, the pressed part 73e is arranged on the support 73 of the drum. The pressed portions 73e and 71o protrude in a direction that crosses the axial direction of the drum 62 and are separated from the drum 62.

On the other hand, as shown in part (a) of Fig. 12 and part (b) of Fig. 12, the drive-side drum flange 63 has a drive-side engaging protrusion 63b, and the coupling projection 63b has a free end portion 63b1 at the free end thereof. The drive transmission member 81 has a coupling recess 81b and a free end portion 81b1 of the coupling recess 81b on the non-drive side. By closing the opening/closing door 13, the cylindrical cam 86 is rotated along the inclined surface portions 86a, 86b along the inclined surface portions 15d, 15e of the drive side plate 15 by middle of the rotation cam connection 85 (the side that approaches cartridge B). With this, the drive transmission member 81 in the retracted position is moved to the non-drive side (the side approaching the cartridge B) in the longitudinal direction by the spring 84 of the drive transmission member. Since the gear teeth of the gear portion 81a and the gear portion 30a are inclined with respect to the direction of travel of the drive transmission member 81, the gear teeth of the gear portion 81a abut against the gear teeth. gear teeth of the gear portion 30a by the movement of the drive transmission member 81. At this time, the movement of the drive transmission member 81 toward the non-drive side is stopped.

Even after the drive transmission member 81 stops, the cylindrical cam 86 continues to move toward the non-drive side, and the drive transmission member 81 and the cylindrical cam 86 separate.

Next, as shown in part (a) of Fig. 1 and Fig. 13, Fig. 18, the drum support 73 has a lower recess surface 73i. The drive transmission element 81 has a lower part 81b2, such as positioning on the lower part of the coupling recess 81b. The engaging recess 81b of the drive transmission member 81 is a hole having a substantially triangular cross section. Viewed from the non-drive side (the cartridge side, the opening side of the recessed portion 81b), the coupling recessed portion 81b is twisted counterclockwise N as it approaches the drive side (the back side of the coupling portion). lowered 81b). The gear portion 81a of the drive transmission member 81 is a helical gear including gear teeth twisted counterclockwise N as they approach the drive side, viewed from the non-drive side (cartridge side). In other words, the coupling recess portion 81b and the gear portion 81a are inclined toward the rear end (fixed end 81c) of the drive transmission member 81 in a direction opposite to the direction of rotation CW of the drive transmission member. 81 (torsion).

The gear part 81a and the coupling recess part 81b are arranged on the axis of the drive transmission member 81, in such a way that the axis of the gear part 81a and the axis of the coupling recess part 81b intersect. overlap each other. In other words, the gear part 81a and the coupling recess part 81b are arranged coaxially (concentrically).

The engaging protrusion 63b of the drive side drum flange 63 has a substantially triangular cross-section and has a protrusion (bulge, protrusion) shape. The coupling protrusion 63b is twisted counterclockwise O from the drive side (the tip side of the coupling protrusion 63b) to the non-drive side (the bottom side of the coupling protrusion 63b) (FIG. 37). In other words, the coupling projection 63b is inclined (bent) in the counterclockwise direction (the direction of rotation of the drum) away from the outside towards the inside of the cartridge in the axial direction.

In addition, in the coupling protrusion 63b, the part (protruding line) that forms the corner (the vertex of the triangle) of the triangular prism is a driving force receiving part which, in fact, receives the driving force from the driving force part. 81b Coupling Recess. The driving force receiving part is inclined in the direction of rotation of the drum inward from the outside of the cartridge in the axial direction. Also, the inner surface (inner peripheral surface) of the coupling recessed part 81b serves as a driving force applying part, for applying the driving force to the coupling projection 63b.

Also, the cross-sectional shape of the engaging protrusion 63b and the engaging recess portion 81b is not strictly a triangle (polygon) because the corners are chamfered or rounded, but is called an approximate triangle (polygon). In other words, the coupling projection 63b is in the shape of a substantially twisted triangular prism (polygonal prism). However, the shape of the engaging projection 63b is not limited to such a shape. The shape of the coupling protrusion 63b can be changed if it can be engaged with the coupling recess 81b, that is, if it can engage with and be driven by it. For example, three protrusions 163a may be provided at the vertices of the triangle shape, where each protrusion 163a is twisted relative to the axial direction of the drum 62 (FIG. 19).

The gear portion 30a of the developing roller gear 30 is a worm gear and has a shape twisted (inclined) clockwise P, from the drive side to the non-drive side (figure 37). In other words, the gear tooth (helical tooth) of the gear part 30a is inclined in the clockwise direction P (the direction of rotation of the developing roller or the developing roller gear) in the axial direction of the developing roller part 30a. gear, from the outside to the inside of the cartridge (twisted). That is, the gear 30a is inclined (twisted) in the direction opposite to the direction of rotation of the drum 62 going from the outside to the inside in the axial direction.

As shown in Fig. 13, the drive transmission member 81 is rotated by the motor (not shown) in a clockwise direction CW (reverse direction of arrow N in Fig. 13), viewed from the non-drive side. (cartridge side). Then, the thrust force (force generated in the axial direction) is generated by interlocking mesh between the helical teeth of the gear part 81a of the drive transmission member 81 and the gear part 30a of the gear 30 of the developing roller. . The force FA in the axial direction (longitudinal direction) is applied to the drive transmission member 81, and the drive transmission member 81 tends to move toward the non-drive side (closer to the cartridge) in the longitudinal direction. In other words, the drive transmission member 81 approaches and contacts the engaging projection 63b.

In particular, in this embodiment, the gear part 81a of the drive transmission member 81 has tooth helicity to move between 5 and 8.7 mm per tooth in the axial direction (FIG. 13). This corresponds to the helix angle of the gear portion 81a being between 15° and 30°. Furthermore, the helix angle of the developing roller gear 30 (the gear part 30a) is also between 15° and 30°. In this embodiment, 20° is selected as the helix angle between the gear portion 81a and the gear portion 30a.

Next, when the phases of the triangular portions of the coupling recess portion 81b and the coupling projection 63b are made to coincide by the rotation of the drive transmission member 81, the coupling projection 63b and the coupling recess portion 81b coupling mesh (couple) with each other.

Then, when the protrusion 63b and the coupling recess part 81b engage, an additional thrust force FC is produced because both the coupling recess part 81b and the coupling protrusion 63b are twisted (inclined) relative to the other. axis.

That is, a force FC directed to the non-drive side in the longitudinal direction (the side approaching the cartridge) is applied to the drive transmission member 81 . This force FC and the force FA described above jointly cause the drive transmission member 81 to move further in the longitudinal direction toward the non-drive side (cartridge approach). In other words, the coupling projection 63 brings the drive transmission member 81 closer to the coupling projection 63b of the cartridge B.

The drive transmission member 81 attracted by the coupling projection 63b is positioned in the longitudinal direction (axial direction) by the free end portion 81b1 of the drive transmission member 81 contacting the lower surface 73i of the recess. drum support 73.

Also, a reaction force FB of force FC acts on the drum 62, and due to this reaction force FB (opposite force), the drum 62 moves in the longitudinal direction toward the drive side (approaching the transmission member drive 81, the outside of cartridge B). In other words, the drum 62 and the engaging protrusion 63b are attracted to the drive transmission member 81 side. With this, the free end part 63b1 of the engaging protrusion 63b of the drum 62 abuts against the lower part 81b2. of the coupling recess 81b. In this way, the drum 62 is also positioned in the axial direction (longitudinal direction).

That is, the engaging projection 63b and the engaging recess portion 81b are attracted toward each other, so that the positions of the drum 62 and the drive transmission member 81 in the axial direction are determined.

In this state, the drive transmission member 81 is in the drive position. In other words, the drive transmission member 81 is in a position to transmit the driving force to the coupling boss 63b and the gear part 30b, respectively.

Also, the center position of the free end portion of the drive transmission member 81 is determined with respect to the drive side drum flange 63 by the triangular aligning action of the coupling recess 81b. In other words, the drive transmission member 81 is aligned with the drum flange 63, and the drive transmission member 81 and the photosensitive member are coaxial. With this, the drive from the drive transmission member 81 to the developing roller gear 30 and the drive side drum flange 63 is transmitted with high precision.

The engagement recessed portion 81b and the engagement boss portion 63b that engages with the engagement recessed portion 81b can also be considered an alignment portion. That is, the engagement between the coupling recess 81b and the coupling projection 63b makes the drive transmission member 81 and the drum coaxial with each other. Especially, the recessed coupling part 81b is called the main assembly side aligning part (the imaging apparatus side aligning part), and the projecting coupling part 63b is called the system side aligning part. cartridge.

As explained above, the engagement of the coupling is assisted by the force FA and the force FC acting on the drive transmission member 81 towards the non-drive side.

Also, by positioning the drive transmission member 81 by the drum support 73 (support member) provided in the cartridge B, it is possible to improve the positional accuracy of the drive transmission member 81 with respect to the cartridge B.

Positional accuracy in the longitudinal direction between the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the drive transmission member 81 is improved, and therefore the width of the portion 30a can be reduced. development roller gear 30 gear. It is possible to reduce the size of cartridge B and the main apparatus assembly A to mount cartridge B.

Summarizing this embodiment, the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 have helical teeth. Helix teeth provide higher gear contact ratios than spur teeth. With this, the rotational precision of the developing roller 30 is improved and the developing roller 30 rotates smoothly.

Also, the direction in which the helical teeth of the gear part 30a and the gear part 81a are inclined is selected so that the force (force FA and force FB) with which the gear part 30a and the gear part 30a is produced is produced. gear portion 81a attract each other. In other words, by rotating in a state that the gear part 30a and the gear part 81 a lock with each other, such a force is produced that the coupling recess part 81 b provided on the drive transmission member 81 and the engaging projection portion 63b provided at the end portion of the photosensitive drum 62A approach each other. With this, the drive transmission member 81 moves toward the cartridge B side, and the engagement recessed portion 81b approaches the engagement protrusion portion 63b. This will contribute to the coupling (engaging) between the coupling recess 81b and the coupling projection 63b. In other words, by rotating in a state where the gear portion 30a and the gear portion 81a are in locking mesh with each other, such a force is produced that the engagement recess portion 81b provided on the member drive transmission 81 and the projection portion 63b provided at the end portion of the photosensitive drum 62 approach each other. With this, the drive transmission member 81 moves toward the cartridge B side, and the engagement recessed portion 81b approaches the engagement protrusion portion 63b. This contributes to the coupling between the coupling recess 81b and the coupling projection 63b.

Also, the direction in which the engagement protrusion 63b (driving force receiving part) is inclined with respect to the axis of the drum, and the direction in which the helical teeth of the gear part 30a of the gear 30 of the drum developing roller are inclined with respect to the axis of the gear part 30a are opposite to each other (FIG. 38). With this, displacement of the drive transmission member 81 is contributed not only by the force generated by the meshing (lock meshing) of the gear part 30a and the gear part 81a, but also by the force (coupling force ) generated by the engagement (engagement by engagement) of the engagement projection 63b and the engagement recess portion 81b. In other words, by rotating the engaging projection 63b and the engaging recess 81b in the engaged state with each other, the engaging projection 63b and the engaging recess 81b are attracted to each other. As a result, the coupling protrusion 63b and the coupling recess 81b stably engage (couple) with each other.

The drive transmission member 81 is pushed toward the coupling projection 63b by the elastic member (drive transmission member spring 84) (part (a) of Fig. 7). According to this embodiment, the force of the drive transmission element spring 84 can be reduced, corresponding to the force FA and the force FC (part (b) of Fig. 13). Then, the frictional force between the drive transmission member spring 84 and the drive transmission member 81, which occurs when the drive transmission member 81 rotates, is also reduced, and thus the torque required to rotate the drive transmission member 81. Additionally, the load applied to the motor for rotating the drive transmission member 81 can also be reduced. Also, the sliding noise produced between the drive transmission member 81 can be reduced. drive transmission element 81 and the spring 84 of the drive transmission element.

Furthermore, in this embodiment, the drive transmission member 81 is forced by the elastic member (spring 84), but the elastic element is not necessarily required. In other words, if the gear portion 81a and the gear portion 30a overlap at least partially in the axial direction, and the gear portion 81a and the gear portion 30a lock with each other when the cartridges are assembled in the main assembly of the device, the elastic element can be eliminated. In other words, in this case, when the gear part 81a rotates, the force for attracting the coupling projection part 63b and the coupling recess part 81b with each other is produced by the meshing between the gear part 81a and the coupling recess part 81a. gear part 30a. That is, even if there is no elastic member (spring 84), the drive transmission member 81 approaches the cartridge B due to the force generated by the interlocking mesh between the gears. This establishes engagement of the mating recess 81b with the mating projection 63b.

In the absence of said elastic member, the frictional force between the elastic member and the drive transmission member 81 does not occur, and therefore, the rotational force torque of the drive transmission member 81 decreases more. Also, it is possible to suppress the sound generated by the sliding movement between the drive transmission member 81 and the elastic member. Furthermore, it is possible to reduce the number of parts of the image forming apparatus, and therefore, it is possible to simplify the structure of the image forming apparatus and reduce the cost.

Also, the engaging protrusion 63b of the drive side drum flange 63 engages with the recess 81b of the drive transmission member 81 in the state that the drive transmission member 81 is rotating. In this case, the coupling protrusion 63b is inclined (crooked) in the direction of rotation of the photosensitive drum inward from the outside of the cartridge, with respect to the axial direction of the drum 62. In other words, the coupling protrusion 63b it is tilted (crooked) along the direction of rotation of the drive transmission member 81, and therefore it is easy to engage the engaging protrusion 63b with the recess portion 81b in rotation.

Also, in this embodiment, the worm gear is used as the developing roller gear 30 meshing with the drive transmission member 81. However, other gear can be used as long as the drive transmission is possible. For example, a thin spur gear 230 which can enter the tooth pitch 81e of the drive transmission member 81 can be used. The thickness of the flat teeth is set to 1 mm or less. Also in this case, the gear portion 81a of the drive transmission member 81 has helical teeth, and therefore the force to drive the drive transmission member 81 to the non-drive side is produced by the interlocking engagement. between gear portion 81a and spur gear 230 (FIG. 21).

Also, in this embodiment, as shown in part (a) and part (b) of Fig. 1, as the cartridge B is viewed from the driving side, the coupling projection 63b (drum 62) rotates in counterclockwise O, such that the development roller gear 30 (the development roller 32) rotates in the clockwise direction P.

However, it is also possible to use a structure in which, as the cartridge B is viewed from the non-drive side, the coupling boss 63b (drum 62) rotates counterclockwise and the gear 30 of the development roller (the roller development 32) rotates clockwise. In other words, the arrangement of the main assembly A and the cartridge B can be modified to make the directions of rotation of the engaging projection 63b (drum 62) and the development roller gear 30 opposite to those in this embodiment. In any case, viewing the coupling boss 63b and the developing roller gear 30 in the same direction, the coupling boss 63b and the developing roller gear 30 rotate in opposite directions. One of these rotates clockwise and the other rotates counterclockwise.

In other words, as the cartridge B is viewed in a direction such that the rotational direction of the coupling boss 63b becomes counterclockwise (in this embodiment, cartridge B viewed from the drive side), the rotational direction of the gear 30 of the development roller is clockwise.

Also, in this embodiment, the developing roller gear 30 is used as the drive input gear, which meshes with the drive transmission member 81, but another gear can be used as the drive input gear.

Fig. 22 shows the drive input gear 88 interlocking with the drive transmission member 81, the development roller gear 80 arranged on the development roller, the idle gears 101 and 102, and the feed gear 103. (agitator gear, developer feed gear). In Fig. 22, the driving force is transmitted from the drive input gear 88 to the developing roller gear 80 by means of an idle gear 101. The idle gear 101 and the developing roller gear 80 are a drive mechanism. drive transmission (cartridge side drive transmission, development side drive transmission) for transmitting a driving force from the drive input gear 88 to the development roller 32.

On the other hand, the idle gear 102 is a gear for transmitting the driving force from the drive input gear 88 to the stirring gear 103. The feed gear 103 is mounted on the feed member 43 (FIG. 3), and the feed member 43 is rotated by the driving force received by the feed gear 103.

In addition, it is also possible to use a series of gears to transmit the driving force between the drive input gear 88 and the developing roller gear 80. At this time, to set the direction of rotation of the developing roller 32 in the In the direction of arrow P (FIG. 1), it is preferable to make the number of idle gears transmitting the driving force between the drive input gear 88 and the developing roller gear 80 odd. In Fig. 22, to simplify the gear train structure, an idle gear structure is shown.

Furthermore, in other words, in relation to the number of gears, to provide the direction of rotation of the developing roller 32 in the direction of the arrow P (FIG. 1), and to transmit the drive to the developing roller 32, the cartridge B it is provided with an odd number of gears. In the structure shown in Fig. 22, the number of gears for transmitting the drive to the development roller 32 is three, that is, the development roller gear 80, the idle gear 101 and the drive input gear 88. On the other hand, in the structure shown in Fig. 1, the number of gears for transmitting the drive to the development roller 32 is one, that is, only the gear of the development roller 32.

In other words, it suffices that the cartridge B is provided with a drive transmission mechanism (a cartridge side drive transmission mechanism, a development side drive transmission mechanism) to rotate the development roller 32 in the same direction of rotation as the drive input gear 88.

That is, viewing the cartridge B in a direction such that the direction of rotation of the drive input gear 88 is clockwise, the direction of rotation of the developing roller 32 also rotates in the clockwise direction. In the structure shown in Fig. 22, the directions of rotation of the drive input gear 88 and the development roller 32 are clockwise when the cartridge B is viewed from the drive side.

Furthermore, in the case of the structure shown in Fig. 1 or the structure shown in Fig. 22, the drive input gear (30, 88) is driven from the drive transmission member 81, regardless of whether the projection 63b coupling “I” receives power. In other words, cartridge B has two input parts (drive input parts) for receiving driving force from outside of cartridge B (i.e., apparatus main assembly A), one for the cleaning unit and one for the cleaning unit. for the developing unit.

In the structure in which the photosensitive drum (cleaning unit) and the developing roller (developing unit) independently receive driving force from the driving transmission member 81, there is an advantage that the rotational stability of the drum is improved. photosensitive drum. This is because there is no need to transmit the driving force (rotational force) between the photosensitive drum and another element (developing roller, for example), and therefore when a rotational unevenness occurs with this different element (developing roller, for example), its rotation unevenness is less likely to affect the rotation of the photosensitive drum.

Also, in the structure of Fig. 22, the force in the direction of the arrow FA (part (b) in Fig. 13) is applied to the drive transmission member 81 to contribute to engagement of the engagement recess portion 81b and the coupling projection 63b. For this, a load (torque) has to be generated when the drive input gear 88 rotates. Conversely, as long as a load is generated to rotate the drive input gear 88, the drive input gear 88 may not be formed to receive the driving force to rotate the developing roller 32.

For example, the drive force received by the drive input gear 88 can be transmitted only to the feed member 43 (FIG. 3) without being transmitted to the developing roller 32. However, in the case of a structure with a cartridge such as includes the development roller 32, it is necessary to separately transmit the driving force to the development roller 32. For example, for cartridge B, a gear or the like is required to transmit the driving force from the drum 62 to the development roller. revealed 32. <Coupling engagement condition>

Next, referring to Figure 1, part (a) of Figure 18, part (b) of Figure 24, part (a) of Figure 25, and part (b) of Figure 25 and Figure 27, the conditions under which the coupling engages will be described. Part (a) of Fig. 24 is a cross-sectional view of the driving part of the image forming apparatus, seen from the direction opposite to the mounting direction of the cartridge B, to explain the distance of the driving part drive transmission. Part (b) of Fig. 24 is a cross-sectional view of the driving part of the image forming apparatus seen from the side of drive, to explain the distance of the drive transmission part. Part (a) of Fig. 25 is a cross-sectional view of the driving part of the image forming apparatus, seen from the driving side, to explain the separation of the coupling part. Part (b) of Fig. 25 is a cross-sectional view of the driving part of the image forming apparatus, seen from the driving side, to explain the separation of the coupling part. Fig. 27 is a sectional view of the image forming apparatus for explaining the range of an adjusting part (stopper), seen from the driving side.

As shown in part (a) of Fig. 1 and Fig. 24, and part (b) of Fig. 24, the drum support 73 is provided with an inclination adjusting part (inclination adjusting part). of movement, position adjusting part, stopper) 73j to regulate the movement of the drive transmission member 81 so as to restrict (suppress) the tilt of the drive transmission member 81.

The drive transmission member 81 has a cylindrical part 81 i (part (a) of Fig. 24) on the non-drive side (the side close to the cartridge B). The cylindrical part 81i is a cylindrical part (protrusion) in which the coupling recess 81b is formed.

As described above, at the stage where the drive transmission member 81 starts to rotate, the gear part 81a of the drive transmission member 81 and the gear part 30a of the developing roller gear 30 are rotated. interlock with each other, as shown in Fig. 9. On the other hand, the engagement recess 81b and the engagement projection 63b are not engaged, or the engagement between them is insufficient. Therefore, when the gear part 81a transmits the driving force to the gear part 30a, the locking force FD (part (b) of Fig. 24) is generated in the gear part 81a by meshing between the gears. gears.

By the locking force FD applied to the drive transmission member 81, the drive transmission member 81 tilts. That is, as described above, only the fixed end 81c (see part (a) of Fig. 24: the end remote from the cartridge B) of the drive transmission element 81, which is the end portion at the drive side, is supported, and therefore, the drive transmission member 81 is tilted with the drive side end portion 81c (fixed end) as the fulcrum. Next, the end (free end, tip) of the drive transmission member 81 is moved to the side where the engagement recess 81b is provided.

If the drive transmission member 81 tilts significantly, the coupling recess 81b cannot engage with the coupling projection 63b. To prevent this, the restriction part 73j is provided in the cartridge B, so that the inclination of the driving transmission member 81 is restricted (regulated) within a certain range. That is, when the drive transmission member 81 tilts, the restraining portion 73j supports the drive transmission member 81, thereby preventing the tilt thereof from increasing.

The adjusting portion 73j of the drum support 73 has an arcuate curved surface portion arranged to face the axis of the drum 62 (the axis of the coupling projection 63b). The restriction part 73j can also be considered as a protruding part, protruding to cover the axis of the drum. The structure is such that between the adjusting part 73i and the drum axis, a space is disposed in which the constituent elements of the process cartridge B are not disposed, and the drive transmission element 81 is disposed in this space. The regulation part 73i faces the space 87 shown in Fig. 1, and the regulation part 73i forms an edge (outer edge) of the space 87.

The restraining portion 73j is disposed at a position where the movement (inclination) of the driving transmission member 81 by the locking force FD can be suppressed.

The direction in which the locking force FD occurs is determined by a transverse pressure angle α of the gear portion 81a (ie, the transverse pressure angle α of the developing roller gear 30). The direction in which the locking force FD is generated is inclined, with respect to the direction (half line) LN extending from the center 62a of the photosensitive drum (that is, the center of the driving transmission member 81) toward the center 30b of the developing roller gear 30, (90 a) degrees towards the upstream AK in the direction of rotation of the photosensitive drum 62.

In the torsion angle worm gear with a helix angle of 20°, the standard angle a is 21.2°. The transverse pressure angles α of the gear portion 81a and the gear portion 30a of this embodiment are also 21.2°. In this case, the inclination of the clamping force FD with respect to the arrow LN is 111.2°. However, other value can be used as the transverse pressure angles of the gear portion 81a and the gear portion 30a, and the locking force direction FD is also different in such a case. The transverse pressure angle a also varies depending on the twist angle of the worm gear, and the transverse pressure angle a is preferably 20.6° or more, and 22.8° or less.

In the part (b) of Fig. 24, when the straight half line FDa extending in the same direction as the locking force direction FD is extended with the center 62a of the photosensitive drum as the starting point, the part of constraint 73j is arranged to traverse the half line FDA. In this case, the half line FDa is a line arranged by tilting (rotating) the half line LN 90 degrees to the upstream side with respect to the direction of rotation of the drum 62, with the center of the drum 62 as the origin (axis, support point). In this embodiment, the half line FDa is inclined 111.2° with respect to the straight half line L ⁿ .

It is not always necessary that the regulation part 73j be disposed on this line FDa, and the regulation part 73j is preferably disposed adjacent to the half line FDa. More specifically, it is desirable that at least a part of the regulating part 73j is disposed somewhere in the range of plus or minus 15° with respect to the half line FDa. The half line FDa is a line obtained by rotating (90 to) degrees the straight half line LN to the upstream side in the direction of rotation of the drum 62. Therefore, the regulating part 73j is preferably in the range of ( 75 a) degrees to (105 a) degrees on the upstream side in the direction of rotation of the drum, with respect to the half straight line LN with the center of the drum 62 as the origin. Considering that the preferable value of the transverse pressure angle a is 20.6° or more and 22.8° or less, the preferable range in which the restriction portion 73j is arranged is 95.6° or more, and 127.8° or less with respect to the LN midline. In this embodiment, the transverse pressure angle a is 21.2 degrees, and therefore, the preferred range of the regulating portion 73j is 96.2° or more, and 126.2° or less.

As another example of the preferred arrangement of the regulation portion 73j, a plurality of regulation portions 73j may be arranged so that they are separately disposed on respective sides of the half line FDa with the half line FDa interposed therebetween (FIG. 26 ). Also in this case, it can be considered that the restriction part 73j is arranged through the line FDa.

Furthermore, it is preferable that the adjusting part 73j is disposed on the upstream side AO (FIG. 16) of the center (axis) of the coupling projection 63b in the mounting direction C of the cartridge (part (a) of FIG. 11). ). This is to prevent the restriction portion 73j from hindering the mounting of cartridge B.

A range (area) in which the adjusting part 73j is disposed on the drum support 73 can also be described as follows.

In a plane perpendicular to the axis of the drum 62 (part (b) of FIG. 24), a straight line LA passing through the center 62a of the drum 62 and the center 30b of the developing roller gear 30 is drawn. At this time, the restriction part 73j is disposed on the side where the charge roller is disposed with respect to the straight line LA (ie, the side indicated by the arrow AL).

Alternatively, the restriction portion 73j is disposed in an area AL opposite to the side on which the drum 62 is exposed (the side on which the drum 62 faces the transfer roller 7) with respect to the line LA passing through the drum center 62a and gear center 30b. In this case, before mounting the cartridge B to the main assembly of the apparatus A, a cover or a shutter for covering the drum 62 may be provided on the cartridge B, and the drum 62 may not be exposed. However, in such a case, the side on which the drum 62 is exposed means the side on which the drum 62 is exposed when the cover, shutter and the like are removed. Also, in the plane perpendicular to the axis of the photosensitive drum 62, the range (area AL) in which the adjusting portion 73j is disposed can also be described as follows, using the circumferential direction (rotational direction) of the photosensitive drum 62.

A half line (home line) LN is drawn extending from the center 62a of the drum 62 toward the center 30b of the gear portion 30a of the developing roller gear 30. The zone AL is an interval (zone) that is greater than 0° and does not exceed 180° to the upstream side (arrow side AK) in the direction of rotation of the drum with respect to the half line LN.

Also, in other words, the interval AL is on the upstream side (arrow side AK), with respect to the direction of rotation O of the drum, of the center point MA between the center 62a of the drum and the center 3b of the gear. of the developing roller, and does not exceed a straight line (extension line) LA passing through the center 6a of the drum 62 and the center 30b of the gear portion 30a of the developing roller gear 30.

Further, in a state that the opening/closing door 13 is open and the driving transmission member 81 is moved to the driving side, the adjusting part 73j is in a position overlapping the gearing part 81a of the driving member. drive transmission 81 in the longitudinal direction. That is, the adjusting portion 73j also overlaps the developing roller gear 30 in the longitudinal direction. As shown in Fig. 34, when the developing roller gear 30 and the timing portion 73j are projected onto the axis line Ax2 of the developing roller gear 30, at least parts of their projected areas overlap each other. Yes. That is, the adjusting part 73j is close to the gear part 81a (the gear part 30a) where the locking force is produced. Therefore, when the locking force received by the drive transmission member 81 is borne by the restraining portion 73j, the bending of the drive transmission element 81.

Also, in the axial direction, at least a part of the restraining portion 73j is on the outer side (side of arrow D1 in Fig. 34) of the coupling projection 63b.

Next, the radial position of the adjusting part 73j will be described with reference to the drum 62 (part (a) of Fig. 24).

The distances shown below are the (distances in the radial direction of the drum 62) measured along a direction perpendicular to the axial direction of the drum 62. Let S be the distance from the axis (center 62a) of the drum 62 to the part regulation 73j. Let U be the radius of the tooth tip of the gear portion 81a of the drive transmission member 81. Let AC be the distance from the center 81j of the drive transmission member 81 to the radially outermost part of the coupling recess. Let AD be the distance from the center 63d of the drive side drum flange 63 to the radially outermost part of the coupling boss 63b. Let AA be the distance between the timing portion 73j and the tooth tip of the gear portion 81a of the drive transmission member 81. And let AB be the amount of deviation between the center of the mating projection 63b and the center of the recess 81b. engagement when the drive transmission member 81 is tilted the clearance amount relative to the timing portion 73j (when the drive transmission member 81 is tilted and the gear portion 81a is in contact with the timing portion 73j) (part (b) of Fig. 25).

Then, the clearance AA between the gear part 81a of the drive transmission member 81 and the adjusting part 73j of the drum support 73 is as follows:

AA = S - U

In the following description, the distance is measured along the axial direction of the drive transmission member 81 from the fixed end 81c which is the fulcrum of the tilt of the drive transmission member 81. Let X be the distance in the axial direction from an end portion 81c of the drive transmission member 81 to the gear portion 81a. Also, let W be the distance in the axial direction from an end portion 81c of the drive transmission member 81 to the coupling recessed portion 81b.

The distance X and the distance W satisfy W > X.

Therefore, the amount of the misalignment AB between the adjusting part 73j and the gear part 81a, at the time when the driving transmission member 81 is inclined the clearance AA, is larger than the clearance AA and is as follow.

AB = AA X (W / X)

Also, let V be the clearance between the engagement protrusion 63b of the drive side drum flange 63 and the engagement recess 81a of the drive transmission member 81, in a situation where there is no misalignment. In this case, the gap V is the minimum value between the distances between surfaces of the two coupling parts (the distance measured along the direction perpendicular to the axis of the drum 62 and the radial distance).

In the state where the phases between the triangular shapes of the couplings are aligned, the shortest gap V is as follows.

V = AC - AD

In order for the coupling to mesh even if the drive transmission member 81 is inclined by the clearance AA and misalignment of the amount of misalignment AB between the couplings occurs, the clearance V between the couplings can satisfy the following.

V = AC - AD > AB

That is, if the magnitude of the misalignment AB is less than the shortest distance V between the coupling protrusion 63b and the coupling recess part 81b, the coupling protrusion 63b and the coupling recess part 81b can tolerate the magnitude of misalignment AB and mesh.

If the phase of the coupling recess 81b with respect to the coupling projection 63b is different, the shortest distance V between the coupling parts is also different. That is, if the phases of the mating portions are not aligned, the shortest clearance V between the mating projection 63b and the mating recess portion 81b is less than (AC-AD). The separation V can be less than the magnitude of the AB misalignment, depending on the cases.

However, if there is at least one phase relationship satisfying "V > AB" between the two mating portions, the mating projection 63b and the mating recess portion 81b are meshed. This is because the coupling recess 81b contacts the coupling projection 63b while rotating. It can be engaged (engaged) with the coupling protrusion 63b at the time that the coupling recess 81b is rotated to an angle such that it satisfies "V > AB".

Furthermore, as the measure of the distance S from the center 62a of the drum 62 to the regulating portion 73i along the radial direction of the drum 62,

S = AA U

Substituting "AB = AA x (W / X)" and "AA = S-U" into "V > AB"

V > (S-U) x (W / X).

It suffices that there is at least one phase relationship between the engagement projection 63b and the engagement recess 81b that satisfies this formula.

Furthermore, the above equation is further modified and the distance condition S is as follows:

S < U V x (X / W)

Furthermore, it is preferable that when the drive transmission member 81 rotates, the restraining part 73j does not come into contact with the gear part 81a, and therefore, it is preferable that the timing part 73j is separated from the gear tip. tooth of gear portion 81a. This is expressed as follows:

S > U

Together with the previous relational expression,

U < S < U V x (X / W)

If the cross-sectional shape of the coupling protrusion 63b and the cross-sectional shape of the coupling recess 81b are substantially equilateral triangles as in this embodiment, the clearance V is maximized when the phases of the coupling portions are aligned. Now substituting the value of V in the previous expression, the necessary interval of S is obtained.

The operation when the coupling engages will be described. Before the engaging recess 81b of the drive transmission member 81 and the engaging projection 63b of the drive side drum flange 63 engage with each other, the locking force FD is applied to the drive transmission member 81. The locking force FD is the force produced by the meshing between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30, as described above.

By the locking force FD, the drive transmission member 81 is tilted, with the drive transmission member support 83 as a fulcrum, in the direction FD in which the locking force is applied, the amount of separation AA between the regulating part 73j of the drum support 73 and the gear part 81a. The misalignment AB of the coupling recess 81b and the coupling projection 63b provided by this inclination is less than the clearance V between the coupling recess 81b and the coupling projection 63b at a predetermined phase. With this, when the drive transmission member 81 rotates, and the phases of the triangles of the coupling recess portion 81b and the coupling protrusion 63b are aligned with each other, the end surfaces of the couplings do not interfere with each other, so such that the coupling recess portion 81b fits around the coupling projection 63b, and they engage with each other.

In this case, an example of dimensions in which the above conditional expression is satisfied when the radius of the drum 62 is 12 mm will be described below.

In this embodiment, the dimensions of each part of the drive transmission member 81 applicable to the drum 62 having a radius of 12 mm are as follows. The distance AC from the center of the coupling recess 81b to the apex of the substantially equilateral triangle shape of the coupling recess 81b is 6.5 mm, and the radius AE of the inscribed circle of the substantially equilateral triangle shape of the coupling recess 81b is coupling is 4.65 mm. The substantially equilateral triangle shape of the coupling recess 81b is not strictly an equilateral triangle but its apex (corner) is chamfered in the shape of an arc. The radius AF of the 81b3 reduction part of the coupling recess part is 4.8mm, the radius U of the circle of the tip of the engagement portion 81a of the coupling recess portion is 12.715 mm, the distance X from an end portion 81c to the end surface of the non-drive side 81 a1 is 30.25 mm, and the distance W from a end portion 81 c to free end portion 81 b1 of the coupling recess is 33.25 mm.

The shortest distance V between the coupling recess 81b and the coupling projection 63b satisfies the following relationship

0 < V < 1.7

The lower limit of V occurs when the size of the triangle shape of the coupling recess 81b is equal to the size of the triangle shape of the coupling projection 63b, and the value of the lower limit of V is "0". On the other hand, the upper limit of V occurs when the distance AC from the center of the coupling projection 63b to the apex is 4.8 mm, which is the radius AF of the reduction portion of the coupling recess 81b. At this time, the clearance V (mm) between the coupling protrusion 63b and the coupling recess 81b is obtained as "1.7 = 6.5 - 4.8".

Substituting each value y V = 1.7 into the formula “U < S < U V x (X / W)" given above,

"12.715 < S < 14.262“ (units in mm).

Next, it will be confirmed that the above is true using two examples.

First, in the first example, the dimensions are shown when the coupling protrusion 63b is made as large as possible within a range that it can engage with the coupling recess 81b. At this time, the clearance V between the engaging projection 63b and the engaging recess 81b is minimal, and therefore, the allowable tilt of the drive transmission member 81 is small. Therefore, in order to reduce the inclination of the driving transmission member 81, it is necessary to make the adjusting part 73j closer to the regular position of the gear part 81a.

On the other hand, in the second example, the dimensions are shown when the coupling protrusion 63b is made as small as possible within the range that it can engage with the coupling recess 81b. In this case, the clearance V between the coupling protrusion 63b and the coupling recess portion 81b is maximized, and therefore, even if the drive transmission member 81 is relatively steeply inclined, the coupling protrusion 63b and the coupling recess 81b can engage with each other. That is, the timing part 73j can relatively tolerate tilting of the driving transmission member 81, and therefore, the timing part 73j can be relatively far apart from the regular position of the gearing part 81a.

In the first example, the size of the engagement protrusion 63b is closest to the maximum, and the magnitude of the engagement radial direction between the engagement protrusion 63b and the engagement recess 81b (the area where both are engaged) is maximized. . In this case, V (the spacing between couplings) approaches the lower (minimum) limit, and therefore S (the distance from the center of the drum 62 to the regulating part 73j) has to approach the lower limit ( 12,715mm).

The distance AD from the center of the engaging projection 63b of the drive side drum flange 63 to the apex thereof is 6.498 mm. As described above, when the coupling protrusion 63b has a dimension slightly smaller than the distance 6.5 mm from the center of the coupling recess 81b to the apex of the triangle, the magnitude of the radial direction of engagement between the parts coupling is substantially maximum. The radius AG of the circle inscribed in a triangle constituting the engaging projection 63b of the drive side drum flange 63 is 4.648 mm. In this case, the substantially triangular shape of the coupling projection 63b is not strictly an equilateral triangle, but one vertex (corner) is chamfered in the shape of an arc.

At this time, the distance S from the center 62a of the drum 62 to the timing portion 73j of the drum support is 12.716 mm, which is somewhat larger than the radius U of the added circle of the gear portion 81a.

With this, the clearance AA between the drum support adjustment part 73j and the drive transmission member gear part 81a is 0.001 mm (= 12.716 - 12.715). In this case, the amount of misalignment AB between the coupling parts when the drive transmission member 81 is inclined the distance AA with respect to the adjusting part 73j is amplified by the difference between the positions of the adjusting part 73j and the coupling part in the longitudinal direction. The magnitude of misalignment AB is 0.0011 mm (= 0.001 x 33.25 / 30.25). Furthermore, the shortest clearance V between the coupling protrusion 63b and the coupling recess 81b when the phases of the coupling parts are aligned is 0.002 mm ("6.5 - 6.498" or "4.65 - 4.648", whichever is less).

Therefore, even if the drive transmission member 81 is tilted due to the locking force, the clearance V between the couplings is greater than the misalignment AB between the coupling parts, so that meshing is possible.

As can be understood from the above description, the radial distance from the center of the drum 62 to the outermost part of the coupling part is preferably greater than 4.8 mm, and the radial distance from the center of the drum 62 up to the regulation part 73j is preferably greater than 12.715 mm.

In the second example, as described above, the size of the engagement protrusion 63b is made as small as possible, and the radial amount of engagement between the engagement protrusion 61b and the engagement recess 81b (the area where both engage) is made as small as possible. At this time, V (the pitch between couplings) approaches the maximum (upper limit) and S (distance from the center of the drum 62 to the timing portion 73j) may be near the upper limit.

The distance AD between the center of the engaging projection 63b of the drive side drum flange 63 and the apex is 4.801 mm. This is a slightly larger value than the 4.8mm radius of the reduction portion 81b3 of the coupling recess 81b, and it is a diameter where the amount of engagement in the radial direction between the couplings is almost minimal. If the distance AD of the coupling projection 63b is shorter than the radius of the reduction portion 81b3, the tip of the projection 63b does not engage with the coupling recess 81b, with the result that the drive transmission is disabled.

At this time, the radius AG of the circle inscribed in the triangle of the coupling projection 63b is 2.951 mm. The distance S between the center 62a of the drum 62 and the adjustment part 73j of the drum support is 14.259 mm. As a result, the clearance AA between the timing portion 73j of the drum support 73 and the gear portion 81a of the drive transmission member 81 is 1.544 mm (= 14.259 - 12.715). In this case, the amount of misalignment AB between the mating portions when the drive transmission member 81 is inclined the amount of clearance AA with respect to the adjusting portion 73j is amplified due to the positional difference in the longitudinal direction between the regulating part 73j and the coupling part, and is 1.697 mm (= 1.544 x 33.25 / 30.25). Furthermore, the clearance V between the coupling protrusion 63b and the coupling recess 81b when the phases of the coupling parts are aligned with each other is 1.699 mm ("6.5 - 4.801" or "4.65 - 2.951", whichever is larger).Therefore, even if the drive transmission member 81 is tilted by the meshing force FD, the clearance V between the couplings is larger than the misalignment AB between the coupling parts, so that the engagement protrusion 63b and engagement recess 81b can be engaged.

As will be understood from the second example, it is preferred that the radial distance from the center of the drum 62 to the outermost part of the coupling projection 63b is greater than 4.8 mm, and that the radial distance from the center of the drum 62 until the restriction part 73j is less than 14.262 mm.

Summarizing the first and second examples, in this embodiment, the radial distance S from the center 62a of the drum 62 to the adjusting portion 73j of the drum support is preferably greater than 12.715 mm and less than 14.262 mm.

In the following, the case where the coupling protrusion 363b having a more general shape is used is taken as an example, without limiting the shape of the coupling protrusion to a substantially regular triangle, and a preferred arrangement will be generally described in relation to with the restriction part 73j. In this case, the shape of the coupling recess is assumed to be a virtually perfect equilateral triangle, for ease of explanation.

First, an example of a coupling protrusion including a general shape is shown in part (a) and part (b) of Fig. 28. The coupling protrusion 363b shown in part (a) and part (b) of Fig. 28 has a substantially cylindrical shape, and further has a projection 363b1 disposed on the outer periphery of the column. The coupling projection 363b receives the driving force via the projection 363b1. Referring to Fig. 27, the case where the regulating part is located furthest from the center of the drum will be described.

First, the minimal equilateral triangle BD circumscribing the coupling shoulder 363b is considered, and this regular triangle BD as a virtual coupling shoulder. In this case, the center of gravity of the equilateral triangle BD is made to coincide with the center of the coupling projection 363b (the center of the drum 62), and the size of the equilateral triangle BD is minimized. Next, the arrangement of the restriction part 73j corresponding to this virtual coupling projection (equilateral triangle DB) will be considered.

A circle inscribed in the imaginary coupling boss (regular triangle BD) is a circle BE, and its radius is BA.

When the coupling recess is in the shape of an equilateral triangle, the coupling recess has to be larger than the equilateral triangle BD in order for the coupling recess to engage with the imaginary coupling boss (equilateral triangle BD). That is, the size of the equilateral triangle BD can also be considered as the lower limit of the size that the coupling recess can have.

Next, the maximum shape that the coupling recess can have will be considered. First of all, the circle BU circumscribing the imaginary coupling protrusion (equilateral triangle BD) is considered, and its radius is AZ. And an equilateral triangle BQ is drawn that has this circle BU as an inscribed circle. When the coupling recess is in the shape of an equilateral triangle, the equilateral triangle BQ is the maximum (upper limit) of the equilateral triangle shape that can be selected as the coupling recess. If the coupling recess is made larger than the equilateral triangle BQ, the coupling recess cannot come into contact with the imaginary coupling projection BD, and therefore drive transmission is impossible. This equilateral triangle BQ is taken as the maximum coupling recess.

Let AY be the shortest distance between the equilateral triangles when these two equilateral triangles BD and BQ are in the same phase. The distance AY corresponds to the difference between the radius (AZ) of the inscribed circle BU, inscribed in the equilateral triangle BQ, and the radius (BA) of the inscribed circle BE, inscribed in the equilateral triangle BD. Namely,

AY = AZ - BA

When the coupling recess is an equilateral triangle, the distance between the imaginary coupling projection and the coupling recess is the aforementioned distance AY as the upper limit. If the misalignment distance of the coupling recess with respect to the virtual coupling projection is less than AY, the coupling recess can be engaged with the imaginary coupling projection.

The distance of misalignment between the couplings is equal to or greater than the distance BC between the tooth tip of the drive transmission member gear portion 81a and the timing portion 73j. Therefore, for the coupling recess to engage with the imaginary coupling boss BD, the clearance BC between the drive transmission member gear portion 81a and the restraining portion 73j has to be at least less than the distance AY. This is shown in the formula

BC < AY

The clearance BC is the difference between the distance BB from the center of the drum to the timing portion 73j and the added circle radius of the gear portion 81a. As for the radius of the added circle of the gear portion 81a, the tooth tip of the gear portion 81a of the drive transmission member may extend to the bottom of the tooth of the gear portion 30a of the roller gear 30 revealed. That is, the tooth tip of the gear portion 81a can be extended to such an extent that it does not reach the bottom of the tooth. If the shortest distance from the center of the drum to the bottom of the developing roller gear 30a is AX, the upper limit of the radius of the added circle 81a of the gear portion 81a is likewise AX.

Therefore, the pitch BC between the tooth tip of the gear part 81a and the regulating part 73j is always greater than "BB-AX", that is,

BC > BB-AX. The distance BB from the center of the drum to the restriction part 73j using the relational expression of "BC > BB-AX" and the expression "BC < AY" mentioned above, satisfies the following conditions:

BB-AX < AY

BB < AY AX

In this case,

AY = AZ - BA = BA (1 /sin 30° - 1) = BA

Therefore,

BB < BA AX

As a necessary condition for the coupling to mesh when the drive transmission member 81 is tilted by the interlocking force between the gears, "BB < BA AX" can be obtained with with respect to the distance BB from the center of the drum of the regulating part 73j.

Next, the case where the regulating part is positioned closest to the center of the drum will be described. In order for the gear portion 81a of the drive transmission member 81 to engage with the gear portion 30a, it is necessary that the radius of the added circle of the gear portion 81a be greater than the distance BF (the distance measured in the direction perpendicular to the drum axis) from the center of the drum 62 to the tooth tip of the developing roller gear portion 30a. Furthermore, it is necessary that the timing portion 73j and the tooth tips of the drive transmission member 81 do not come into contact with each other during image formation. That is, it is necessary that the distance BB (the distance measured in the direction perpendicular to the axis of the drum) from the center of the drum 62 to the regulating part 73j is greater than the distance BF (the distance measured in a direction perpendicular to the axis of the second shaft) from the center of the drum 62 to the tooth tip of the developing roller gear part 30a. This is necessary to fulfill the following from the previous two conditions.

BB > BF

Summarized together with "BB < BA AX" described above, it is preferable that the adjusting portion 73j is disposed at an interval that satisfies the following relationship with respect to the center of the drum (the axis of the drum, the axis of the input coupling).

BF < BB < AX BA

The definition of each value is summarized as follows.

BB: the distance measured from the center of the photosensitive element (the axis of the photosensitive element, the axis of the coupling projection) to the adjusting portion 73j measured along the direction perpendicular to the axis of the photosensitive element;

BA: the radius of the inscribed circle, inscribed in the equilateral triangle when the minimum equilateral triangle circumscribing the coupling boss is drawn, while aligning the center of gravity of the equilateral triangle with the axial line of the drum (axial line of the coupling boss). coupling);

AX: The distance from the center of the photosensitive element (the axis of rotation of the coupling boss) to the bottom of the development roller gear (bottom of the input gear) measured along the direction perpendicular to the axis of the element photosensitive; and

BF: the minimum distance measured from the center of rotation (axis) of the photosensitive element to the tooth tip of the input gear portion (gear portion 30a) measured along the direction perpendicular to the axis of the photosensitive element.

In this embodiment, the adjusting part 73j is formed by a continuous surface. More specifically, the regulating part 73j is a curved surface (circular arc surface) which opens towards the axis line of the drum 62 and curves in the shape of an arc. In other words, it is a bay shape (bay part) open towards the drum axis 62.

However, as shown in the perspective view of the cartridge in Figure 26, the regulating part 89j may be formed by a series of parts (several surfaces 89j) intermittent in the direction of rotation of the drum 62. Also in this case, by connecting a series of intermittent parts, the regulating part can be considered to take a bay shape (bay part) opening to the axis of the drum 62.

That is, there are differences depending on whether the regulation part is a continuous part or a series of intermittent parts, but both the restriction part shown in Fig. 1 and the restriction part shown in Fig. 26 are considered to have the shape arc (a bay shape, a curved surface part, a curved part) that opens to the axis of the drum 62.

Also, in this embodiment, as a means of aligning the center of the drive transmission member 81 with the center of the drum 62, the triangle-shaped aligning action of the coupling protrusion 63b and the recess portion 81b of the drum is used. coupling. That is, the coupling projection 63b and the coupling recess 81b are in contact at three points, so that the axis of the coupling projection 63b and the axis of the coupling recess 81b are aligned with each other. By making the drive transmission member 81 and the photosensitive drum coaxial, the accuracy of the center distance (axis distance) between the gear portion 81a and the gear portion 30a can be easily maintained, and the drive is transmitted stably to the developing roller gear 30.

However, one of the drive transmission member 81 and the drive side drum flange 63 may be provided with a cylindrical protrusion (protrusion), and the other may be provided with a hole to engage with the protrusion. Even with such a structure, the axis of the drive transmission member 81 and the axis of the drum 62 may overlap. Figure 38 shows a modified example. The drive transmission member 181 shown in Fig. 38 has a protrusion (bulge) 181c at the center of the engagement recess 181b. The projection 181c is arranged to overlap the axis of the drive transmission 181 and is a projection that protrudes along its axis. On the other hand, the engaging projection shown in Fig. 38 has a recess (recess) for engaging with the projection 181c at the center thereof. The recess is arranged to overlap the axis of rotation of drum 62, and is a recess that is recessed along this axis. By making the drive transmission member 81 and the photosensitive drum coaxial, the accuracy of the center distance (axis distance) between the gear portion 81a and the gear portion 30a can be easily maintained, and the drive is transmitted stably to the developing roller gear 30.

Next, the arrangement of the engaging projections 63b in the longitudinal direction (drum axial direction) will be described. As shown in Fig. 18, the drive side drum flange 63 has a flange portion 63c. The cleaning frame 71 is provided with a drum adjusting rib 71m (a drum adjusting part, a drum longitudinal position adjusting part, a drum axial direction position adjusting part).

The drum adjusting rib 71m is disposed on the non-drive side of the flange portion 63c of the drive side drum flange 63, with respect to the longitudinal direction, and facing the flange portion 63c with a gap Between both.

When the drum 62 moves to the non-drive side by an amount above this clearance, the flange 63c and the drum regulating rib 71m come into contact with each other, and the movement of the drum 62 is restricted. That is, the drum 62 does not move in the longitudinal direction (axial direction) beyond a predetermined range. With this, the positional accuracy in the longitudinal direction of the engagement protrusion 63b of the drive side drum flange 63 before the engagement protrusion 63b of the drive side drum flange 63 engages with the recess is improved. 81b coupling. Therefore, even if the amount of displacement of the drive transmission member 81 in the longitudinal direction is reduced, the coupling protrusion 63b and the coupling recess 81b can be engaged with each other. By decreasing the amount of displacement of the driving transmission member 81 in the longitudinal direction, the size of the main assembly of the apparatus A can be reduced.

Next, the arrangement of the gear portion 30a of the developing roller gear 30 in the longitudinal direction (drum axial direction) will be described. As shown in Fig. 18, the developing roller gear 30 has an end surface 30a2 on the non-drive side of the gear portion 30a. The developing container 23 is provided with a developing roller gear restraining rib 23d (a gear adjusting part, a gear longitudinal position adjusting part, a gear axis line position adjusting part, etc.). gear).

The developing roller gear restraining rib 23d is disposed on the non-drive side, in the axial direction with respect to the end surface of the non-drive side 30a2 of the gear portion 30a, and facing the end surface of the gear portion 30a. non-drive side 30a2 with a gap between them. Thereby, the developing roller gear restraining rib 23d provided on the drive side of the cartridge B restrains the movement of the developing roller gear 30 toward the non-drive side in the longitudinal direction. Thus, the positional accuracy in the axial direction of the gear part 30a of the developing roller gear 30 before the gear part 30a of the developing roller gear 30 engages with the gear part 81a of the developing roller gear 30 is improved. drive transmission member 81. Therefore, the gear width of the gear portion 30a of the developing roller gear 30 can be reduced. In this way, the size of the cartridge B and the main assembly of the apparatus A in which the cartridge B is mounted can be reduced.

<Cartridge removal>

Referring to Figures 7, 24 and 25, removal of cartridge B from the main assembly of apparatus A will be described.

As shown in Fig. 7, when the opening and closing door 13 is rotated and opened, the cylindrical cam 86 moves while rotating along the inclined surface portions 86a and 86b by means of the connection 85. of rotation cam, until the end surface portion 86c of the cylindrical cam 86 and the end surface portion 15f of the drive side plate 15 abut against the drive side in the axial direction. And, as the cylindrical cam 86 moves, the drive transmission member 81 can move to the drive side in the axial direction (the side away from cartridge B).

In this case, as shown in part (a) and part (b) of Fig. 24 and part (a) of Fig. 25, the radial teeth of the gear part 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 apply the amount to be applied to the amount AH. To break the mesh between the gear part 81a and the gear part 30a, the gear part 81a is it has to move in a direction away from the gear portion 30a by an amount equal to or greater than the mesh amount AH between the gear portions. Therefore, the adjusting part 73j of the drum support 73 is arranged so as not to hinder the movement of the driving transmission member 81 when the gear part 81a is separated from the gear part 30a. The direction in which the gear portion 81a of the drive transmission member 81 moves away from the gear portion 30a of the developing roller gear 30 is indicated by the arrow AI along the direction in which it extends the line connecting the center 81j of the drive transmission member 81 and the center 30b of the developing roller gear 30. It is preferred that the restriction part 73j is not disposed in the direction of the arrow AI. That is, it is preferable that the adjusting part 73j is not arranged to cross the straight line LA, and that the driving transmission member 81 does not come into contact with the restraining part 73j when the gear part 81a is disengaged. of the gear portion 30a.

It is preferable that, when the gear portion 81a is disengaged from the gear portion 30a, the drive transmission member 81 does not come into contact with the recess peripheral surface 73k of the drum support 73. In this state in which the door 13 is open (part (a) and part (b) of Fig. 7), the driving transmission element 81 retracts to a position such that it does not come into contact with the circumferential surface 73k of recess of the support 73 of the drum.

That is, as shown in the part (a) of Fig. 24, the drive transmission member 81 is in the retracted position to such an extent that the coupling with the coupling projection 63b is broken. Therefore, in the longitudinal direction of the drive transmission member 81, the free end of the drive transmission member 81 is substantially at the same position as the free end of the circumferential undercut surface 73k, or on the left side of the end. free circumferential undercut surface 73k. In this state, even if the drive transmission member 81 tilts in an attempt to break the lock mesh between the gear portion 81a and the gear portion 30a, the drive transmission member 81 and the peripheral surface 73k of recess do not come into contact with each other.

It is also conceivable that the amount of movement of the drive transmission member 81 when moving back is small, and that the free end of the drive transmission member 81 in the retracted position is disposed on the right side of the free end of the lowered circumferential surface. 73k. In such a case, contact between the drive transmission member 81 and the circumferential recess surface 73k can be prevented if the following conditions are met.

Let Z be the distance in the radial direction from the center 62a of the drum 62 to the peripheral recess surface 73k of the drum support 73. Let Y be the radial distance from the center 81j of the drive transmission member 81 to the outer peripheral surface of the cylindrical portion 81 i of the drive transmission member 81. Let AJ be the radial distance at the gap between the recess peripheral surface 73k and the cylindrical part 81i.

In this case, the separation AJ fulfills the following.

AJ = Z - Y

AJ > AH

That is, a recess portion is provided around the drum 62. And the drive transmission member 81 can be moved within the range that the inner peripheral surface (recess peripheral surface 73k) of the recess portion does not come into contact with gear portion 81a.

The radial position of the recessed peripheral surface 73k of the drum support 73 may be such that the distance Z from the center 62a of the drum 62 satisfies the following:

Z > AH Y

With the above structure, when the cartridge B is removed from the main assembly A of the apparatus, the drive transmission member 81 can be tilted, in the direction away from D, by an amount greater than the mesh amount AH between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30. And the disengagement is effected between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30, so that the cartridge B can be smoothly pulled out from the main assembly A of the apparatus. As described above, the drive transmission member 81 moves toward the mating portion on the cartridge side due to the thrust force caused by the meshing of the worm gears with each other.

Also, the drive transmission member 81 is moved (tilted) by the force produced by the interlocking of the gears, but the amount of movement (tilt amount) is regulated by the restraining portion provided on the cartridge side. With this, it is ensured that the meshing (coupling) between the drive transmission member 81 and the cartridge-side coupling portion ensures reliable drive transmission.

In addition, since the drive transmission member 81 is provided with a gap that allows the drive transmission member 81 to move in the radial direction beyond the meshing height of the gear, the disengagement between the gears when the cartridge B is removed from the main assembly of the apparatus is carried out smoothly. That is, the cartridge can be easily removed.

Also, in this embodiment, the coupling projection 63b is attached to the drum 62, but a movable coupling projection can be provided. For example, the coupling 263b shown in Fig. 20 is movable in the axial direction with respect to the drum 62, and is pushed by the spring 94 toward the driving side in a state where it does not receive any external force. When the cartridge B is mounted on the main assembly A, the end 263a of the coupling 263b comes into contact with the driving transmission element 81. The coupling projection 263b can move back to the non-drive side (the side far from the transmission element). drive 81) while the spring 94 is contracted by the force received from the drive transmission member 81. With such a structure, it is not absolutely necessary to retract the drive transmission member 81 to such an extent that it does not come into contact with the mating projection 263b. That is, the withdrawal amount of the drive transmission member 81 interrelated with the opening of the opening/closing door 13 (FIG. 2) can be reduced by the amount that the engaging projection 263b can move back. That is, the size of the main assembly A can be reduced. The end part 263a of the coupling projection 263b is an inclined part (inclined surface, beveled surface). With such a structure, when the end portion 263a comes into contact with the drive transmission member 81 at the time of cartridge mounting and dismounting, the end portion 263a tends to receive a force in the recoil direction from the portion 263b. of the coupling boss. However, the present invention is not limited to such a structure. For example, the contact part on the side of the drive transmission member 81 that comes into contact with the coupling projection 263b may be an inclined part.

Another modification is shown in Fig. 23. In this embodiment, the drum 62 is driven by the engagement between the drive transmission member 81 and the coupling boss 63b. However, as shown in Fig. 23, the drive of the drum 62 may be carried out by the gears 330b, 95b. In the structure shown in Fig. 23, the developing roller gear 330 includes not only a gear portion 330a (input gear portion) for receiving drive from the gear portion 81a of the drive transmission member 81, but also a gear part 330b (output gear part) for delivering a driving force to the drum 62. In addition, the drum flange 95 attached to the end part of the drum 62 has a gear part 95b (output gear part). inlet) to receive the driving force from the gear portion 330b, instead of including the engagement protrusion... In addition, the drum flange 95 has a cylindrical portion 95a.

In this case, the cylindrical portion 95a provided at the end portion of the drum 62 functions as a positioning portion for positioning the drive transmission member 81 by engaging with the engaging recess portion 81b provided at the tip of the transmission member. drive 81.

Both the recessed portion 81b and the cylindrical portion 95a act as an alignment portion to align the axes of the recess 81 of the drive transmission member and the drum 62 with each other. When the coupling recess 81b and the cylindrical portion 95a engage with each other, the axes of the drum 62 and the drive transmission member 81 are substantially overlapped, and both are arranged coaxially. In this case, the coupling recess 81b may be referred to as a main assembly side alignment portion (alignment recess portion), and the cylindrical portion 95a may be referred to as a cartridge side alignment portion (alignment boss). .

Strictly speaking, the outer peripheral surface of the cylindrical portion 95a corresponds to the alignment portion on the cartridge side. Also, the reduction portion 81b3 of the coupling projection 81b corresponds to the alignment portion of the main assembly side. The circular reduction part 81b3 engages with the outer peripheral surface of the cylindrical part 95a, thereby aligning the drum 62 and the drive transmission member 81 with each other.

In the cartridge shown in Fig. 23, due to the meshing between the gear part 30a of the gear 30 and the gear part 81a of the drive transmission member 81, a force is produced which attracts the coupling recess part 81b with each other. and the cylindrical part 95a, by the same action as in the embodiment described above. By the drive transmission between the gear part 30a and the gear part 81a, the coupling recess part 81b and the cylindrical part 95a mesh with each other. In this case, it is An inclined (conical, beveled) part 95a1 (part (b) of Fig. 23) is arranged on the tip edge of the cylindrical part 95a, so that the mating recessed part 81b and the cylindrical part 95a are easily engaged with each other. Yes. That is, the diameter of the cylindrical part 95a decreases towards the tip thereof.

As described above, when the coupling protrusion 63b is disposed at the end part of the drum 62, the coupling recess part 81b functions as an output coupling to transmit the driving force to the coupling protrusion 63b. Furthermore, in the case where the coupling protrusion 63b is substantially triangular, as the coupling recess 81b is coupled to the coupling protrusion 63b, the drive transmission member 81 is centered. Therefore, the coupling recess 81b functions as a centering (alignment) part as well.

On the other hand, in the case where the cylindrical part 95a is provided at the end part of the drum 62, such as in the structure shown in part (a) of Fig. 23, the coupling recessed part 81b does not serve as a coupling part (output coupling), but only serves as a centering recess (main assembly side alignment part).

That is, the coupling recess portion 81b serves as the output coupling and as the aligning portion of the main assembly (the aligning recess portion), and the function of the coupling recess portion 81b provided by the structure of the drum 62 is either or both of the function of the engaging recess portion and that of the centering portion.

In addition, although the outer periphery of the alignment part on the cartridge side shown in Fig. 23 is the cylindrical part 95a that forms a complete circle, the present invention is not limited to such a structure. Fig. 35 shows an example of the shape of the alignment part, as a schematic view.

Portion (a) of Fig. 35 shows a state in which the cylindrical portion 95a shown in Fig. 23 is arranged on the flange 63 of the drum. In contrast, in part (b) of Fig. 35, the shape of the aligning part 95b constitutes only a part of a circle. If the circular arc portion of the aligning portion 95b is sufficiently larger than the circular arc shape of the reducing portion 81b3, the aligning portion 95b has a centering action.

The distance (radius) from the center of the drum to the outermost parts of the aligning parts 95a, 95b corresponds to the radius of the reduction part 81b3. The radius of the reduction part 81b3 is 4.8 mm, and therefore the distance (radius) from the center of the drum to the outermost parts of the aligning parts 95a, 95b, 95c is 4.8 mm. mm or less, and the closer it is to 4.8 mm, the better the alignment effect.

In this embodiment, the coupling recessed part 81b which is the main assembly side alignment part has a substantially triangular shape to transmit drive when engaged with the coupling boss part 63b, and an arcuate reduction part 81b3 is provided. arranged in a part of one side of a triangular shape. However, when it is not necessary for the main assembly side alignment unit to transmit the drive to the drum 62, the main assembly side alignment part may take another form. For example, the main assembly side alignment portion may be a substantially circular recess portion. In the case of such a main assembly side aligning section, the aligning part 95c shown in part (c) of Fig. 35 can be used as the cartridge side aligning part. The centering part shown in part (c) of Fig. 35 has a structure in which a plurality of projections 95c are arranged in a circular shape. That is, the circumscribed circle (circle shown by a broken line) of the projection 95c is a circle coaxial with the drum. Also, this circumscribed circle has a size corresponding to the recess portion of the main assembly side alignment portion. That is, the radius of the circumscribed circle is not greater than 4.8 mm.

Any of the structures shown in part (a), part (b) and part (c) of Fig. 35 can be considered as an alignment part that is substantially coaxial with the drum. That is, each of the alignment portions 95a, 95b, 95c is arranged to be centered on the axis line of the drum.

Strictly speaking, the outer peripheral surfaces of the aligning portions 95a, 95b, 95c, that is, the portions facing the opposite side of the drum axis line (in other words, the portions facing the outside in the radial direction of the drum ) function as alignment parts. The outer circumferential surface that functions as the alignment part extends to surround the axis of the drum.

Each of the alignment portions 95a, 95b, 95c is exposed to the outside of the cartridge in the axial direction.

Furthermore, it is preferable that the cartridge structure shown in Fig. 23 also has the adjusting part 73j described above. In addition, the positional relationship (dimensional relationship) between the developing roller gear 30 and the regulating part 73j with respect to the aligning part can be similarly consider the relationship (dimensional relationship) between the gear 30 of the developing roller and the regulating portion 73j with respect to the protrusion 63b of the cartridge.

For the reason described above, for example, for the lower limit of the distance BB from the center of the drum to the center of the regulating portion 73j, the following relationship holds.

BF < BB

BB: the distance measured from the center of the photosensitive element (the axis of the photosensitive element, the axis of the coupling projection) to the adjusting portion 73j along the direction perpendicular to the axis of the photosensitive element.

BF: the minimum distance measured from the center of rotation (axis) of the photosensitive element to the tooth tip of the input gear portion (gear portion 30a) along the direction perpendicular to the axis of the photosensitive element.

The upper limit of the distance BB will be considered. It is preferred that the amount of misalignment generated between the engagement recessed portion 81b and the alignment portion 95a, when the motion transmission member 81 is tilted until the engagement portion 81a contacts the restraining portion 73j, satisfy the following relation. That is, it is preferable that an inclined portion 95a1 (part (a) of Fig. 23) is provided at the tip of the aligning portion 95a, but since the width of the inclined portion 95a is measured along the direction radial of the drum, that the width of the inclined portion 95a is greater than the magnitude of the misalignment. If this relationship is satisfied, even if misalignment occurs, the inclined part 95a1 of the aligning part 95a contacts the edge of the coupling recessed part 81b to assist the engagement between the coupling recessed part 81b and the coupling part. 95th alignment.

The difference between the distance BB and the radius U of the circle of the tip of the gear portion 81a is "BB-U", and the amount of the misalignment becomes larger than "BB-U".

Therefore, at least the width BX of the inclined portion 95a has to be larger than "BB-U". Also, the radius U of the added circle of the gear portion 81a is smaller than the distance AX from the center of the drum to the root of the developing roller gear. Therefore, the width BX of the inclined portion 95a is larger than "BB-AX".

BX > BB-AX

This is modified as follows:

BB < BX AX

BB: the distance measured from the center of the photosensitive element (the axis of the photosensitive element, the axis of the coupling projection) to the adjusting portion 73j along the direction perpendicular to the axis of the photosensitive element.

BX: the width of the inclined portion 95a measured along the radial direction of the photosensitive element.

AX: The distance measured from the axis of the photosensitive element to the root of the development roller gear along the direction perpendicular to the axis of the photosensitive element.

In short, it holds that "BF < BB < BX AX".

In the structure shown in Fig. 23, the cylindrical part 95a is arranged in the drum 62. Alternatively, the alignment part, such as the cylindrical part 95a, may be arranged in the frame of the cleaning unit 60 (i.e., drum support 73). That is, it is also conceivable that the drum support 73 covers the end part of the drum 62, and that the drum support 73 is provided with the alignment part. In addition, it is also possible to use an engaging structure with the cylindrical portion 81 i (part (a) of Fig. 13) of the drive transmission member 81, instead of the recess portion 81 b of the drive transmission member 81. , such as the alignment part on the side of the cartridge.

In the modification shown in Fig. 36, a circular arc projection 173a for contacting the periphery of the cylindrical portion 81 i is provided on the drum support 173. Part (a) of Fig. 36 is a perspective view of the cartridge, and part (b) of Fig. 36 is a sectional view showing a state in which the alignment portions of the cartridge and the drive element of the main assembly are engaged with each other. In this modified example, the projection 173a is engaged with the cylindrical portion 81 i to provide an alignment portion for the alignment of the drive transmission member 81. More particularly, the inner circumferential surface of the projection 173a facing the axis side of the drum (in other words, facing the radially inner side of the drum) is the alignment part.

This alignment part is provided on the drum support 173, not on the drum flange 195. Therefore, the drum flange 195 has a gear part 195a for receiving the driving force from the developing roller gear, but does not have the alignment part.

The center of the alignment portion is arranged to overlap the axis line of the drum. That is, the projection 173a is arranged to be substantially coaxial with the drum. In other words, the inner circumferential surface of the projection 173a facing the drum axis line side is arranged to surround the drum axis. A constriction (inclined part) is provided at the tip edge of the protrusion 173a, so that the cylindrical part 81i can be easily inserted into the internal space of the protrusion 173a when the protrusion tip 173a hits the cylindrical part 81i.

The distance (radius) from the axis of the drum to the alignment part (protrusion 173a) corresponds to the radius of the cylindrical part 81 i. If the radius of the cylindrical part 81 i is 7.05 mm, the radius of the projection 173a is preferably 7.05 mm or more.

The projection 173a also functions as a restraining part (stopper) to suppress tilting and movement of the drive transmission member 81 by contacting the cylindrical part 81 i . That is, the projection 173a can also serve as the restriction part 73j (FIG. 24). The structure in which the adjusting part is formed to come into contact with the cylindrical part 81 i will be described below in Embodiment 2. In this case, an inclined part (taper, bevel) is provided at the tip of the protrusion 173a. , and when the drive transmission member 81 is tilted, the tip of the cylindrical part 81 i comes into contact with the tilted part, so as to contribute to the meshing between the cylindrical part 81 i and the projection 173a. That is, the inner circumferential surface of the projection 173a has a diameter that increases toward the tip of the projection 173a.

The relative functions, materials, shapes and arrangements, and the like, of the constituent parts described in connection with this embodiment and each modification described above, are not intended to limit the scope of the present invention solely thereto, unless otherwise specified.

<Embodiment 2>

An embodiment of Embodiment 2 of the present invention will now be described with reference to Fig. 29, part (a) of Fig. 30, part (b) of Fig. 30, part (c) of Fig. 30 , part (a) of Fig. 31 and part (b) of Fig. 31. Fig. 29 is a perspective view of a cartridge for explaining the adjustment part of the drive transmission member. Part (a) of Fig. 30 is a cross-sectional view of the driving part of the image forming apparatus, seen from the direction opposite to the mounting direction of the cartridge, to explain the adjustment of the transmission part drive. Part (b) of Fig. 30 is a cross-sectional view of the driving part of the image forming apparatus, seen from the driving side, for explaining the adjustment of the driving transmission part. Part (c) of Fig. 30 is a cross-sectional view of the driving part of the image forming apparatus, seen from the driving side, to explain the adjustment of the driving transmission part. Part (a) of Fig. 31 is a cross-sectional view of the driving part of the image forming apparatus, seen from the driving side, for explaining the adjustment of the driving transmission part. Part (b) of Fig. 31 is a cross-sectional view of the driving part of the image forming apparatus, seen from the upstream side of the process cartridge mounting direction, to explain the driving part. drive transmission.

In this embodiment, different parts of the above-described embodiment will be described in detail. In particular, materials, shapes and the like are the same as in the aforementioned embodiment, except where otherwise indicated. For such parts, the same reference numerals will be assigned and the detailed description thereof will be omitted.

As shown in parts (a) of Figs. 29 and 30, part (b) of Fig. 30 and part (c) of Fig. 30, the drum support 90 is provided with a recess portion in around the projection part of the coupling part. And a restricting part 90k1 for restricting the movement of the drive transmission member 91 is provided as a small diameter part (a part in which the inner diameter of the recess part is made smaller than the other parts) inside of the peripheral surface 90k of the recess (the inner peripheral surface of the recess portion). The adjusting part 90k1 is an arcuate curved surface part facing the axial line side of the drum.

The adjusting part 90k1 is an adjusting part (stopper) for suppressing movement and tilting of the drive transmission member 91, and is a part corresponding to the adjusting part 73j (FIG. 1, FIG. 24 and the like) in the embodiment 1. In the following, the regulation part 90k1 of this embodiment, in particular the parts different from the restriction part 73j of embodiment 1, will be described in detail.

The part that adjusts the inclination of the drive transmission member 91 by the restraining part 90k1 is a cylindrical part 91 i (cylindrical part) provided at a free end part of the non-drive side in the axial direction of the drive transmission member. drive 91. The cylindrical part 91 i corresponds to a cylindrical projection in which a coupling recess is formed.

In the state that the opening and closing door 13 is opened and the driving transmission member 91 moves on the driving side (direction away from the cartridge side), the adjusting part 90k1 overlaps the cylindrical part 91i of the cartridge. drive transmission element 91 in the axial direction.

As shown in Fig. 39, in this embodiment, at least a part of the timing portion 90k1 in the axial direction is located outside (on the arrow D1 side) of the outer circumferential surface 63b2 in the timing portion. input coupling (the coupling boss 63b). In this case, the outer circumferential surface 63b2 is a part (drive receiving part) which receives the driving force from the coupling recess. In particular, at least a part of the restraining portion 90k1 is disposed on the outside of the front end 63b1 of the coupling projection 63b.

Furthermore, at least a part of the regulating part 90k1 is arranged to overlap with the input coupling part (the coupling projection 63b) in the axial direction. That is, when the coupling projection 63b and the adjusting portion 90k1 project onto the axis Ax1 of the drum, at least part of the projected portions thereof mutually overlap each other. In other words, at least a part of the regulating part 90k1 is arranged to face the input coupling part (the coupling protrusion 63b) provided at the end part of the drum.

The regulating part 90k1 can also be considered as a protruding part that protrudes to cover the axis of the drum.

In this case, it has been explained that in the embodiment 1 (part (a), part (b) of Fig. 24, part (a) of Fig. 25) the following is true.

AB = AA X (W / X)

S = AA U

V > AB

V > (S - U) x (W / X)

U < S < U V x (X / W)

In this embodiment, among the dimensions shown in part (a) of Fig. 30, part (b) thereof, and part (c) thereof, AU corresponds to V and AS corresponds to S.

Also, AT corresponds to AA, and AP corresponds to U.

Also, W = X, and (W / X) = 1.

Next, in this embodiment, when the drive transmission member 91 is tilted until it comes into contact with the adjusting portion 90k1, the conditions under which the engaging protrusion 63b and the engaging recess portion can be engaged with each other yes they are the following, according to the same analysis as in realization 1.

AB = AT

AS = AT AP

AU > AT

UA > (AS-AP)

AP < AS < AP AU

In other words, if there is at least one phase relationship satisfying "AU > AT = AS-AP" between the mating projection and the mating recess, the mating portions engage (couple) with each other.

In this case,

AB: The amount of misalignment between couplings measured along the direction perpendicular to the axis of the drum.

AT: the distance from the driving transmission element 91 (cylindrical part 91 i) to the regulating part 90k1, measured along the direction perpendicular to the axis of the drum.

AS: The distance from the axis of the drum (the axis of the coupling boss) to the regulating part 90k1, measured along the direction perpendicular to the axis of the drum.

AP: the radius of the cylindrical part 91 i of the drive transmission element 91.

In the embodiment 1, the gear portion 81a of the drive transmission member 81 is regulated by the restriction portion 73j.

On the contrary, in this embodiment, the cylindrical portion 91i that forms the outer peripheral surface of the coupling recess 91b is regulated by the regulating portion 90k1.

Therefore, the positions of the adjusting part 90k1 and the coupling recess part 91b in the axial direction are substantially the same.

Compared with the case where the gear part 81a of the drive transmission member 81 is regulated by the restraining part (part (a) of Fig. 24), in this embodiment the tilt of the drive transmission member 91 can be adjusted. accurately regulate.

With this, even if the gap between the coupling recess 91 and the coupling projection 63b is small, they can engage with each other. Since the dimensions (sizes) of the coupling recess 91 and the coupling projection 63b are close to each other, the accuracy of the drive transmission is improved. In this case, an example of set dimensions when the radius of the drum 62 is 12 mm will be described below. First, the dimensions of the respective parts of the drive transmission member 91 applicable to the drum 62 having a radius of 12 mm in this embodiment are the same as those of the drive transmission member 81 in the embodiment 1, and are as follows: the distance AJ from the center of the coupling recess 91b to the apex of the substantially equilateral triangle of the recess 91b is 6.5 mm, and the radius AK of the roughly triangular inscribed circle of the coupling recess 91b is 4.65mm In this case, the shape of the substantially equilateral triangle of the recessed portion 91b is not a pure equilateral triangle, but the apex corner is chamfered in the shape of an arc. Also, the radius AN of the reduction portion 91b3 of the coupling recess 91b is 4.8mm, and the radius AP of the cylindrical portion 91i of the drive transmission member 91 is 7.05mm.

The shortest distance AU between the coupling recess 91b and the coupling projection 63b satisfies the following relationship.

0 < AU < 1.7

AU is the lower limit when the size of the triangular shape of the coupling recess 91b is equal to the size of the triangular shape of the coupling projection 63b. On the other hand, AU is the upper limit when the distance from the center of the coupling protrusion 63b to the apex is 4.8 mm, which is the radius AC of the reduction portion of the coupling recess 91b. At this time, the clearance AU between the coupling protrusion 63b and the coupling recess 81b is "1.7 = 6.5 - 4.8".

Therefore, substituting each value y AU = 1.7 into the expression "AP < AS < AP AU" shown above,

"7.05 < S < 8.75".

The fact that the above equation holds will be confirmed using two examples.

In the first example, the dimensions are shown when the coupling protrusion 63b is enlarged to the maximum within a range that can be engaged with the coupling recess 91b. In this case, the clearance AU between the coupling projection 63b and the coupling recess 91b approaches the lower limit, and therefore, the allowable inclination of the drive transmission member 81 becomes small. Therefore, in order to reduce the inclination of the driving transmission member 91, it is necessary to make the adjusting part 90k1 closer to the regular position of the cylindrical part 91i.

In the second example, the dimensions are shown when the coupling protrusion 63b is made minimum in the range that it can engage with the coupling recess 91b. The clearance AU between the coupling protrusion 63b and the coupling recess 91b approaches the upper limit, and therefore the coupling protrusion 63b and the coupling recess 91b can engage with each other, even if the transmission element drive 81 is relatively steeply sloped. That is, the regulation part 73j can safely tolerate The inclination of the driving transmission member 91 is relatively considerable, and therefore the restriction part 93j can be relatively far apart from the regular position of the cylindrical part 91i.

In the first example, the coupling projection 63b is maximized to maximize the radial amount of coupling between the coupling portions.

The distance AQ from the center of the coupling protrusion 63b of the drive side drum flange 63 to the apex is somewhat less than the distance a J (6.5 mm) from the center of the coupling recess to the apex of the triangle , which is 6,498 mm. At this time, the radius AR of the inscribed circle in a triangle, of the mating convexity 63b of the drive side drum flange 63, is 4.648 mm.

Also, the radius AP of the cylindrical portion 91 i of the drive transmission element 91 is 7.05 mm, and therefore the distance AS from the center of the drum 62 to the regulating portion 90k1 of the drum support is of 7,051 mm, which is somewhat larger than the AP radius.

As a result, the clearance AT between the adjusting part 90k1 of the drum support and the cylindrical part 91i of the driving transmission element is 0.001 mm (= 7.051 - 7.05). Furthermore, the clearance AU between the coupling protrusion 63b and the coupling recess 91b when the phase of the coupling part is in alignment is 0.002 mm ("6.5 - 6.498" or "4.65 - 4.648", the Therefore, even if the drive transmission member 91 tilts due to the locking force, the clearance AU between the couplings is larger than the misalignment AT between the coupling parts, and therefore the engaging protrusion 63b and the engaging recess 91b can be engaged with each other.

In the first example, it is preferable that the distance in the radial direction from the center of the drum 62 to the regulating portion 90k1 is made larger than 7.05mm.

In the second example, the coupling projection 63b is minimized, so that the amount of engagement between the coupling parts is minimal.

The distance AQ from the center to the apex of the coupling protrusion 63b provided on the drive side drum flange 63 becomes 4.801 mm, somewhat larger than the radius AN of the coupling recess reduction portion 91b3, larger than 4.8mm At this time, the radius AR of the inscribed circle inscribed in the triangle shape of the coupling boss is 2.951 mm.

The distance AS of the adjusting part 90k1 of the drum support from the center of the drum 62 is 8.749 mm. With this, the clearance AT between the adjusting part 90k1 of the drum support 90 and the gear part 91a of the drive transmission member 91 is 1.698 mm (= 8.748 - 7.05). Furthermore, the clearance AU between the coupling protrusion 63b and the coupling recess 91b when the phase of the coupling part is in alignment is 1.699 mm ("6.5 - 4,801" and "4.65 - 2,951", the Therefore, even if the drive transmission member 91 tilts due to the locking force, the clearance AU between the couplings is larger than the misalignment AT between the coupling parts, and therefore the coupling parts can mesh with each other.

From the second example, it is understood that the radial distance from the center of the drum 62 to the regulating portion 90k1 of the drum support is preferably less than 8.75 mm.

In other words, it is preferred that the distance in the radial direction from the center of the drum 62 to the adjusting part 90k1 of the drum support is greater than 7.05 mm and less than 8.75 mm.

The shape of the engaging projection provided on the barrel 62 is not limited to a substantially equilateral triangle, and a preferred arrangement of the adjusting part will be considered, in a case of a more general shape. In this case, for convenience the shape of the coupling recess is assumed to be the equilateral triangle. In this case, the coupling protrusion 363b (Figs. 27 and 28) described above is used as a coupling protrusion having a general shape.

First, the upper limit of the distance from the drum axis to the regulating part 90k1 is considered, using the regulating part 90k1 and the drive transmission member 191 shown in Fig. 31.

The position of the restriction part 90k1 depends on the radius of the cylindrical part 191i of the driving transmission element 191. That is, as the radius of the cylindrical part 191i increases, it is necessary to move the regulating part 90k1 away from the axis of the drum. First, as shown in Fig. 31, it is assumed that the diameter of the cylindrical portion 191i of the drive transmission element 191 is larger than the diameter of the gear portion 191a (output gear portion) of the drive transmission element. drive transmission gear 191. At this time, the cylindrical part 191i is arranged to be sandwiched between the roller part 132a of the developing roller 132 and the developing roller gear 30, and the cylindrical part 191i faces the part 132b. from development roller shaft 132.

The distance from the center (axis) of the drum 62 to the regulating part 90k1 is a distance BG (distance measured in the direction perpendicular to the axis of the drum). The distance from the center of the drum 62 to the development roller axis is taken as the distance BK (the distance taken in the direction perpendicular to the axis of the drum).

In this case, it is preferable that the cylindrical part 191i does not interfere with the developing roller shaft part 32b when the driving transmission member 191 is tilted, so that the cylindrical part 191i comes in contact with the drive part 191i. 90k1 regulation. That is, it is desired to restrict the movement of the cylindrical part 191i by the restriction part 90k1, so that at least the cylindrical part 191i does not tilt beyond the axis of the developing roller. Therefore, it is preferable that the distance BG from the center of the drum to the metering portion 90k1 is less than the distance BK from the center of the drum to the axis of the developing roller 132.

BG < BK

Next, referring to Fig. 31, the lower limit of the distance from the center of the drum to the timing portion 90k1 will be considered. The smaller equilateral triangle BO circumscribing the coupling shoulder 363b (FIG. 28) is taken as a hypothetical coupling shoulder. The center of gravity of the equilateral triangle BO is adjusted to be at the center of the coupling boss 363b.

A circle inscribed in the imaginary coupling boss (regular triangle BO) is a circle BP, and its radius is the radius BH. In this case, in order for the hypothetical coupling protrusion BO to engage with the coupling recess portion provided on the cylindrical portion 191i, it is necessary that the cylindrical portion 191i of the drive transmission member be larger than this inscribed circle BP. This is because, if the cylindrical part 191i is smaller than the inscribed circle BP of the hypothetical coupling boss BO, an output coupling part for transmitting the drive to the hypothetical coupling boss cannot be formed in the cylindrical part 191i. BO.

The distance BG from the center of the drum to the regulating part 90k1 is greater than the radius of the cylindrical part 191i, and therefore the distance BG is greater than the radius BH of the inscribed surface BP.

Therefore, the distance BG from the center of the drum of the regulating part 90k1 satisfies

BH < BG

That is, the preferred range of the regulation part 90k1 is as follows

BH < BG < BK

Next, another preferred range of the regulating part 90k1 will be described using the driving transmission element 291 shown in Fig. 32.

In Fig. 32, the cylindrical portion 291i of the drive transmission member 291 has a smaller diameter than the gear portion 291a, and is arranged to face the gear 30 of the developing roller. If the diameter of the cylindrical part 191i is enlarged, as shown in Fig. 31, the cylindrical part 191i cannot be arranged in front of the developing roller gear 30, and it is necessary to arrange the cylindrical part 191i in front of the developing part. development roller shaft. In such a case, it is necessary to increase the length of the developing roller shaft portion, or to increase the length of the drive transmission member. On the contrary, if the drive transmission member cylindrical part 291 i is arranged on the front side of the developing roller gear 30, as shown in Fig. 32, it is not necessary to increase the lengths of the shaft part 232b. of the developing roller 232 and the drive transmission member 291, and thus it is possible to reduce the size of the cartridges and image forming apparatuses.

First, referring to Fig. 32, the upper limit of the distance from the center of the drum to the timing portion 90k1 will be considered.

The distance from the center of the drum 162 to the regulating part 90k1 is a distance BG (the distance measured in a direction perpendicular to the axis of the drum). The shortest distance from the center of the drum 162 to the tooth tip of the gear portion of the developing roller gear 30 is a distance BJ (the distance measured in a direction perpendicular to the axis of the drum). In order to prevent the cylindrical part 291 i from interfering with the developing roller gear 30 when the timing part 90k1 comes in contact with the cylindrical part 291 i, it is preferable that the distance BG from the center of the drum to the timing part 90k1 becomes shorter than the distance BJ from the center of the drum to the tooth tip of the development roller gear.

Therefore,

BG > BJ

In the following, the lower limit of the distance from the center of the drum to the regulation part 90k1 will be considered. The minimum circle circumscribing the coupling projection 163a is BS, and its radius is the radius BL. In this case, the circle BS is arranged concentrically (coaxially) with the drum 162.

In this case, if the cylindrical part 291 i of the drive transmission member 291 is larger than the circle BS, a coupling recess surrounding the entire circumference of the coupling projection 163a may be formed in the cylindrical part 291 i.

In this way, the strength of the output coupling part (coupling recess) can be improved, and the meshing between the couplings can be stabilized.

When the radius of the cylindrical part 291i is larger than the radius BL of the circle BS, the distance BG from the center of the drum to the regulating part 90k1 is also larger than the radius BL and therefore

BG < BL

That is, the range of the regulation part 90j is as follows

BJ < BG < BL

Together with "BJ < BG < BL" and "BH < BG < BK" mentioned above, the preferred range relative to the regulation part can be defined as follows:

BH < BJ < BG < BL < BK

The definition of each value is summarized as follows.

BH: The radius of the inscribed circle, inscribed in the equilateral triangle, when the minimum equilateral triangle circumscribing the coupling boss (input coupling part) is drawn while aligning the center of gravity of the equilateral triangle with the axis of the drum ( the axis of the coupling boss).

BJ: the shortest distance from the drum axis to the tooth tip of gear part 30a (input gear part), measured along the direction perpendicular to the drum axis.

BG: the distance from the center of the drum to the regulating part, measured along the direction perpendicular to the axis of the drum.

BL: the radius of the circumscribed circle, when the minimum circumscribed circle circumscribing the coupling protrusion (input coupling part) is drawn coaxially with the drum.

BK: The distance from the drum axis to the development roller gear axis (development roller axis), measured along the direction perpendicular to the drum axis.

The function, material, shape, and relative arrangement of the components described in the embodiments or modifications thereof are not intended to limit the scope of the present invention, unless otherwise specified.

[INDUSTRY APPLICABILITY]

An imaging process cartridge including a structure for receiving an input of a driving force from the outside is disclosed.

[Reference numerals]

30: Development Roller Gear

30a: gear part

32: development roller (developer transport element)

62: drum (electrophotographic photosensitive drum)

62a: drum center

63: drive side drum flange (driven transmission element)

63b: coupling boss

Claims (48)

1. Process cartridge removably mountable in a main assembly of an electrophotographic imaging apparatus, said process cartridge comprising: a photosensitive element; an engaging portion disposed at an end portion of said photosensitive member and including a driving force receiving portion for receiving a driving force for rotating said photosensitive member from outside said process cartridge; and a gear portion including gear teeth for receiving, independently of said coupling portion, a driving force from outside said process cartridge; wherein said gear teeth are helical gear teeth, and include an exposed portion, exposed to the outside of said process cartridge, wherein at least a portion of said exposed portion is disposed outside said driving force receiving portion in an axial direction of said photosensitive member and faces an axis of said photosensitive member, and wherein the shortest distance from the axis of said photosensitive element to a tooth tip of said gear portion, measured along a direction perpendicular to the axis of said photosensitive element, is not less than 90%, and not more than 110 % of a radius of said photosensitive element. 2. Process cartridge according to claim 1, wherein each of said gear teeth is inclined towards a direction of rotational movement of said gear portion, from the outside of said photosensitive element towards the inside thereof in the axial direction of said photosensitive element. The process cartridge of claim 2, wherein, viewed in a direction such that said photosensitive element rotates counterclockwise, each of said gear teeth tilts clockwise, from the outside of said photosensitive element toward the inside thereof in the axial direction of said photosensitive element. The process cartridge of claim 2 or 3, wherein said process cartridge is configured to be mounted to and detached from said main assembly of said electrophotographic imaging apparatus in a direction substantially perpendicular to the axis of said photosensitive element. Process cartridge according to any one of claims 1 to 4, wherein said driving force receiving portion is inclined in the direction of rotational movement of said photosensitive element, from the outside of said photosensitive element towards the inside. interior thereof, in the axial direction of said photosensitive element. 6. Process cartridge according to any of claims 1 to 5, further comprising a developer transport element configured to carry a developer for developing a latent image formed on said photosensitive element. The process cartridge of claim 6, wherein said developer transport member is rotated by driving force received by said gear portion. Process cartridge according to claim 6 or 7, wherein, viewed in a direction such that said gear portion rotates clockwise, said developer transport member is rotatable in a clockwise direction. 9. Process cartridge according to any one of claims 6 to 8, wherein said gear portion and said developer transport member are arranged coaxially with each other. A process cartridge according to any one of claims 6 to 9, further comprising a developing gear disposed on said developer transport member, wherein said developing gear includes said gear portion. 11. Process cartridge according to any of claims 6 to 8, further comprising a drive input gear including said gear portion, a developer gear disposed on said developer transport member, and at least , an idle gear for transmitting drive force from said drive input gear to said developing gear. 12. Process cartridge according to claim 11, wherein the number of said free gears is an odd number. 13. Process cartridge according to claim 11 or 12, in which the number of free gears is one. 14. Process cartridge according to any of claims 6 to 13, in which, as seen in one direction wherein said photosensitive member rotates counterclockwise, said gear portion and said developer transport member are configured to rotate clockwise. A process cartridge according to any one of claims 6 to 14, further comprising separation maintaining members mounted to said developer carrier at opposite end portions of said developer carrier, said developer carriers being configured gap maintaining members for maintaining a gap between said developer transporting member and said photosensitive member, by being in contact with said photosensitive member. 16. Process cartridge according to any of claims 1 to 15, wherein the center distance between said gear part and said coupling part is variable. 17. Process cartridge, according to claim 16, further comprising a first unit including said coupling part, and a second unit including said gear part, wherein the distance between the axes of said gear part and said coupling portion are changed by displacement of said second unit with respect to said first unit. 18. Process cartridge according to claim 17, wherein said second unit is rotatably connected with said first unit. 19. Process cartridge according to any of claims 1 to 18, further comprising a stop disposed on the same side as said coupling portion with respect to the axial direction, said stop facing the axis of said photosensitive element and protruding outward in the axial direction. 20. Process cartridge according to claim 19, wherein at least a part of said stop is disposed externally, beyond a free end of said coupling part. 21. Process cartridge according to claim 19 or 20, wherein in a plane perpendicular to the axis of said photosensitive element, said stop is disposed in an angular range of 0° to 180° about the axis of said photosensitive element from a half line extending from the axis of said photosensitive element to an axis of said gear portion toward an upstream side in the direction of rotational movement of said photosensitive element. 22. Process cartridge according to any of claims 19 to 21, wherein, in a plane perpendicular to the axis of said photosensitive element, said stop is arranged on a side opposite to a side on which said photosensitive element is exposed , with respect to a line passing through the axis of said photosensitive element and the axis of said gear part. 23. Process cartridge according to any of claims 19 to 22, further comprising a loading element for loading said photosensitive element, wherein said stop is arranged on the provided side of said loading element, with respect to the line passing through the axis of said photosensitive element and the axis of said gear portion in a plane perpendicular to an axis of said photosensitive element. 24. Process cartridge, according to any of claims 19 to 23, in which, in a plane perpendicular to the axis of said photosensitive element, said stop is arranged to traverse an inclined line (90+a) degrees about the axis of said photosensitive element, from a half line extending from the axis of said photosensitive element to the axis of the gear part towards an upstream side with respect to the direction of rotational movement of said photosensitive element, where a is an angle transverse pressure of said gear part. 25. Process cartridge according to any of claims 19 to 24, in which, in a plane perpendicular to the axis of said photosensitive element, at least a part of said stop is arranged in an angular interval of (75+a ) to (105+a) about the axis of said photosensitive element from a half line extending from the axis of said photosensitive element to the axis of the gear part towards an upstream side with respect to the direction of movement of rotation of said photosensitive element, where a is a transverse pressure angle of said gear part. 26. Process cartridge according to any of claims 19 to 25, wherein, in a plane perpendicular to the axis of said photosensitive element, the distance from the axis of said photosensitive element to said stop is greater than the shortest distance from the axis of the photosensitive element to said tooth tip of said gear part, and less than the distance from the axis of said photosensitive element to the axis of said gear part. 27. Process cartridge according to any one of claims 19 to 26, wherein a distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to said stop is greater than the nearest distance short measure along the direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to the tooth tip of said gear portion from the axis of said photosensitive element. 28. Process cartridge according to any of claims 19 to 27, wherein said stop is arranged in a position that satisfies BB < AX+BA, where BB is a distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to said stop, and BA is a radius of an inscribed circle inscribing a minimum equilateral triangle circumscribing said part of coupling and having a center of gravity at the axis of said photosensitive element, and AX is a distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to the bottom of a tooth of said gear part. 29. Process cartridge according to any of claims 19 to 26, wherein the distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to said stop is greater than a radius of an inscribed circle inscribing a minimum equilateral triangle circumscribing said mating portion and having a center of gravity at the axis of said photosensitive element. 30. Process cartridge according to any of claims 19 to 29, wherein a distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to said stop is less than a distance measured along the direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to the axis of said gear portion. 31. Process cartridge according to any of claims 19 to 30, wherein a distance measured along a direction perpendicular to the axis of said photosensitive element from the axis of said photosensitive element to said stop is less than a radius of a minimum circumscribed circle circumscribing said coupling portion and being coaxial with said photosensitive element. 32. The process cartridge according to any one of claims 19 to 31, wherein said stop defines a bay portion opening toward the axis of said photosensitive element. 33. Process cartridge according to any of claims 19 to 32, wherein said stop has a curved surface that opens towards the axis of said photosensitive element. 34. Process cartridge according to any of claims 19 to 33, wherein said stop comprises a series of discrete parts. 35. Process cartridge according to any of claims 19 to 34, wherein, when said engaging portion and said stop project onto the axis of said photosensitive element, at least portions of the projected areas of said portion of gear and said stop overlap each other. 36. Process cartridge according to any of claims 19 to 35, wherein, in a plane perpendicular to the axis of said photosensitive element, the distance from the axis of said photosensitive element to said stop is greater than 12.715 mm and less than 14,262mm. 37. Process cartridge according to any of claims 1 to 36, further comprising a loading element for loading said photosensitive element, wherein, in a plane perpendicular to the axis of said photosensitive element, the axis of said part gear is arranged in an angular range of 64° to 190° about the axis of said photosensitive element from a half line extending from the axis of said photosensitive element to the axis of said load element towards a downstream side with respect to the direction of rotation of said photosensitive element. 38. Process cartridge according to any of claims 1 to 37, further comprising an agitator element for agitating the developer by driving force received by said gear portion. 39. Process cartridge according to any of claims 1 to 38, wherein said coupling part is in the form of a protrusion. 40. Process cartridge according to any one of claims 1 to 39, wherein said coupling portion is in the form of a substantially triangular twisted prism. 41. Process cartridge according to any of claims 1 to 40, wherein, in a cross section of said process cartridge taken along a line perpendicular to the axis of said photosensitive element passing through said exposed portion , when an imaginary circle is drawn that has a radius equal to the distance shortest from the axis of said photosensitive element to said tooth tip of said gear portion and which is coaxial with said photosensitive element, the interior of the imaginary circle is empty space. 42. Process cartridge according to any of claims 1 to 41, further comprising a positioned portion that is disposed on a side of said process cartridge on which said coupling portion is disposed, with respect to the axial direction of said photosensitive element, and protruding into said process cartridge in the axial direction of said photosensitive element, wherein, when said positioned part and said photosensitive element are projected onto the axis of said photosensitive element, at least parts of the projection areas of said positioned part and said photosensitive element overlap each other. 43. Process cartridge according to any one of claims 1 to 42, further comprising a positioned portion that is disposed on a side of said process cartridge where said mating portion is disposed, with respect to the axial direction of said photosensitive element, and protruding into said process cartridge in the axial direction of said photosensitive element, a coupling element provided with said coupling part and mounted on one end of said photosensitive element, wherein, when said part positioned and said coupling element are projected onto the axis of said photosensitive element, at least parts of the projection areas of said positioned part and said coupling element overlap each other. 44. The process cartridge according to any one of claims 1 to 43, further comprising a slit provided on a side of said process cartridge where said engaging portion is provided, with respect to the axial direction of said photosensitive element. 45. The process cartridge of claim 44, wherein said slit is configured to engage with said main assembly of said electrophotographic imaging apparatus to position said cartridge in the axial direction of the photosensitive element. 46. Process cartridge according to claim 44 or 45, wherein said slit extends in a direction perpendicular to the axial direction of said photosensitive element. 47. Process cartridge according to any of claims 1 to 46, wherein the shortest distance from the axis of said photosensitive element to said tooth tip of said gear portion, measured along the direction perpendicular to the axis of said photosensitive element, is not less than 93%, and not more than 107% of the radius of said photosensitive element. 48. Electrophotographic imaging apparatus, comprising: a main assembly; and a process cartridge according to any of claims 1 to 47.